RESULTS: Differences in calibration of current hCG assays are moderate. Mean recovery of the current International Standard (IS), hCG IS 75/589, was 107% (range 93% to 126%), whereas that of the IRR 99/688 for hCG was 139% (range 109%–164%). Betweenmethod variation for the latter (CV 12.3%) was also greater than for IS 75/589 (CV 8.8%). Recognition of hCG varied markedly (CV 37%). Most assays l...

Ectopic production and secretion of hormones by a wide variety of tumors has been known for decades. Initially, ectopic hormone secretion was recognized by signs and symptoms of excess circulating biologically active hormone. With development of more sophisticated assay techniques, biologically inactive fragments and "big" forms of authentic hormones have been identified in these syndromes. Rec...

The present study is designed to elucidate certain biological characteristics of urinary chorionic gonadotropin and to see what differences could be demonstrated between HCG in normal pregnancy and in the trophoblastic diseases. We have attempted the biological characterization of HCG using crude HCG and the purified HCG (12 ,000 I.U./mg) by zone electrophoresis on starch grain and chromatograp...

OBJECTIVE To determine the average within person biological variability of free-β human chorionic gonadotrophin (free hCGβ), intact hCG and pregnancy-associated plasma protein A (PAPP-A), and to establish analytical goals for the measurement of these markers when used in first trimester screening. METHODS Free hCGβ, PAPP-A and intact hCG were measured on paired first trimester samples collect...

Human chorionic gonadotropin (HCG) is an important tumor marker in the diagnosis and monitoring of treatment response childhood cancers such as germ cell tumors liver tumors. The effect chronic kidney disease (CKD) on increased HCG not a well-researched issue. elevation unknown cause only causes diagnostic confusion, but also economic loss by necessitating many unnecessary examinations.In curre...

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...

nonsignificant differences between cutoffs for serum and plasma and between assays are encouraging regarding the ease of interpretation by clinicians and laboratories. Also encouraging were improvements in the analytical sensitivity of these newergeneration assays. Interestingly, only 3 samples were identified as above the 99th percentile by all 3 assays. The mechanisms responsible for this lac...

Goal: The chorionic plate (or “fetal surface”) of the human placenta is drawn as round, with the umbilical cord inserted roughly at the center, but variability of this shape is common. The average shape of the chorionic plate has never been established. The goal of this work is to measure the average shape in a birth cohort. Materials and Methods: 1227 placentas collected from a prospective coh...