Elevated maternal serum human chorionic gonadotropin increases the chance of adverse pregnancy outcome.
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Chorionic Gonadotropin↗
Biomedical subjects
W MacMahon
Publications and source records attributed to W MacMahon.
Prospective evaluation of maternal serum human chorionic gonadotropin levels in 3428 pregnancies.
As part of a multicenter prospective study, second-trimester human chorionic gonadotropin and alpha-fetoprotein concentrations were evaluated. Data included maternal age, human chorionic gonadotropin level, alpha-fetoprotein level, weight, race, and pregnancy outcome of 3428 pregnancies at between 15 and 20 weeks' gestation. The results of the study indicate that human chorionic gonadotropin levels decrease as maternal weight increases, that weight-adjusted human chorionic gonadotropin levels for Oriental and black women are higher than for white or Hispanic women, and that twin pregnancies have higher human chorionic gonadotropin levels than singleton pregnancies. Of 255 pregnancies that did not have normal outcomes, 54 (21.2%) had human chorionic gonadotropin levels greater than 2.0 multiples of the median and 26 (10.2%) had alpha-fetoprotein levels greater than 2.5 multiples of the median. Of 11 pregnancies with fetal aneuploidy, 6 (54.5%) had human chorionic gonadotropin levels greater than 2.0 multiples of the median. It is concluded that in human chorionic gonadotropin screening programs for fetal Down syndrome, weight and race adjustments are necessary for accurate risk assessment.
Aneuploidy↗
Follow-up of elevated maternal serum alpha-fetoprotein levels: ultrasonography only or amniocentesis?
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Amniocentesis↗
Interaction of cyclosporin A with human lipoproteins.
The ultracentrifugal fractionation of human serum after previous incubation with cyclosporin A showed that, in healthy fasting individuals, 8% of cyclosporin A was found in the very low density lipoproteins (VLDL), 31% in the low density lipoproteins (LDL), 46% in the high density lipoproteins (HDL) and 15% in the non-lipoprotein protein fraction. In non-fasted, healthy and in non-fasted, lipaemic individuals, 7 and 6% of cyclosporin A was found in chylomicrons, 9 and 13% in VLDL, 28 and 30% in LDL, 39 and 37% in HDL, and 12 and 13% in the non-lipoprotein protein fraction, respectively. In patients receiving cyclosporin A the distribution varied from 12 to 19% in VLDL, 21 to 28% in LDL, 33 to 43% in HDL, and 13 to 20% in non-lipoprotein proteins. The interaction between cyclosporin A and isolated normal human lipoproteins was also studied by ultrafiltration. All lipoproteins exhibited a non-saturable, low affinity, high capacity uptake for cyclosporin A. Analysis of the uptake by phospholipid vesicles showed a similar uptake, suggesting that cyclosporin A dissolves in the lipophilic portion of the lipoprotein molecule rather than being associated with specific binding sites.
Cyclosporins↗
A simplified ultrafiltration method for determination of serum free cortisol.
We describe the suitability of the Amicon MPS-1 centrifugal ultrafiltration device and the YMB membrane for measuring free cortisol in serum. The method combines two independent assays: total cortisol and the ultrafiltrate fraction of added [3H]cortisol. The unbound fraction is determined in 0.25-0.30 ml of ultrafiltrate collected from 0.6 to 1 ml of serum that has been equilibrated with [3H]cortisol at 37 degrees C for 20 min. The assay is rapid (less than 1 h), practical ( no more than 0.6 ml of serum is necessary) and repeatable (CV: 3.8% within-assay and 12.2% in different assays). Error introduced in free cortisol measurement due to dilution effects in dialysis is systematically defined, and the effect of tracer purity on the ultrafiltration method is examined. Dialyzed sera from normal men and women, from patients with Cushing's disease and adrenal insufficiency, and from pregnant women gave ultrafiltration results that accurately duplicated those obtained by previous dialysis.
Adsorption↗
A simple ultrafiltration method for determining unbound estradiol in serum.
The Amicon MPS-1 centrifugal ultrafiltration device and the YMT membrane were used to measure free estradiol in serum. Two independent assays were required. The first measured total estradiol-17 beta and the second ultrafiltrable fraction. The unbound fraction was determined by counting [3H]estradiol-17 beta in 0.15-0.3 mL ultrafiltrates of 0.5 to 1 mL of serum that had been equilibrated with [3H]estradiol-17 beta at 37 degrees C. The assay is rapid (1 h), practicable (requires 0.6 mL serum) and reproducible (CV 4.6% within assay and 6.5% between assays). Samples from apparently healthy men and women and from pregnant women gave results that agreed with those obtained by equilibrium dialysis. The percentages of free serum estradiol-17 beta were similar during both early and late follicular phases of the menstrual cycle. Samples from women with hirsutism gave values for total and free estradiol-17 beta which were not significantly different from those of normal females when no consideration was given to the phase of the menstrual cycle. The means for both of these female groups were significantly different from those of males.
Adult↗
An improved ultrafiltration method for determining free testosterone in serum.
In this method, we use the Amicon MPS-1 centrifugal ultrafiltration device and the YMB membrane in measuring free testosterone in serum. Two independent assays are combined: total testosterone and the ultrafiltrable fraction of added [3H]testosterone. The unbound fraction is determined in 0.15-0.5 mL ultrafiltrates of 0.6 to 1 mL of variably diluted serum that has been equilibrated with [3H]testosterone at 37 degrees C. The assay is rapid (less than 1 h), practicable (requires 0.6 mL of serum), and reproducible (CV 3.2% within assay, 3.9% between assays). Accuracy was evaluated as the fraction of free testosterone in the ultrafiltrate of dialyzed serum vs that in a prior dialysate; they were the same confirming the validity of the free testosterone measurement. Samples from ostensibly healthy men and women and from hirsute and pregnant women gave results that agreed with those obtained by equilibrium dialysis. Total testosterone concentrations for normal and hirsute women showed considerable overlap, but data on free testosterone concentrations in these populations were better resolved.
Adult↗