Subcutaneous versus intramuscular administration of human chorionic gonadotropin during an in vitro fertilization cycle

OBJECTIVE: To confirm that hCG levels in follicular fluid and serum would be comparable between i.m. and s.c. administration of purified hCG. DESIGN: In a prospective study, serum and follicular fluid levels of hCG after an i.m. or s.c. injection of 10,000 IU of hCG were evaluated 36 hours after injection, that is, at the time of oocyte retrieval. SETTING: This study was carried out in a university-affiliated IVF program. PATIENT(S): Forty women undergoing oocyte retrieval were entered into the study at the time of egg retrieval, that is, 36 hours after hCG administration. INTERVENTION(S): S.c. or i.m. injection of hCG. MAIN OUTCOME MEASURE(S): Serum and follicular fluid concentrations of hCG were evaluated 36 hours after injection at the time of oocyte retrieval. RESULT(S): There was a significantly higher serum hCG level in the s.c. group (348.6 +/- 98 IU/L) vs. the i.m. group (259.0 +/- 115 IU/L) and a significantly higher follicular fluid hCG level in the s.c. vs. the i.m. group (233.5 +/- 85 vs. 143.4 +/- 134 IU/L). CONCLUSION(S): After purified hCG administration via the s.c. route, both serum and follicular fluid levels are greater compared with the i.m. route.     

Hemodynamic changes induced by urinary human chorionic gonadotropin and recombinant luteinizing hormone used for inducing final follicular maturation and luteinization

OBJECTIVE: To compare the safety of recombinant human luteinizing hormone (LH) with that of urinary hCG in terms of the hemodynamic changes when they are used to induce final follicular maturation in patients undergoing in vitro fertilization (IVF). A secondary end point was efficacy in terms of IVF outcome. DESIGN: Prospective, randomized clinical trial. SETTING: University teaching hospital. PATIENT(S): Thirty IVF patients. INTERVENTION(S): Ovarian stimulation was induced with FSH under pituitary suppression. Patients were randomized to receive either hCG or recombinant human LH as a trigger of oocyte maturation (5,000 IU) and for luteal phase support (5,000 IU, 2,500 IU, and 2,500 IU on the day of follicular aspiration, 2 days later, and 5 days later, respectively). MAIN OUTCOME MEASURE(S): Mean arterial pressure, cardiac output, peripheral vascular resistance, and serum levels of progesterone, plasma concentrations of aldosterone, norepinephrine, and plasma renin activity were measured in all patients on postovulatory day 7 of the spontaneous menstrual cycle preceding IVF (baseline) and 7 days after the hCG/recombinant human LH ovulatory injection during the IVF cycle. RESULT(S): Ovarian response and IVF outcome (pregnancy rate, 60%) were similar in both treatment groups. On the seventh day after hCG/recombinant human LH administration, the peripheral vascular resistance was significantly lower and serum progesterone concentrations significantly higher in the hCG group as compared with the recombinant human LH group. The percentage change from baseline values during IVF cycles in all hemodynamic and neurohormonal variables investigated was higher (albeit not statistically different) in the group treated with hCG vs. the group treated with recombinant human LH. CONCLUSION(S): Recombinant human LH is associated with less intense circulatory changes than hCG when it is given to induce final follicular maturation and luteal phase support in IVF procedures.     

Effect of ovarian stimulation with recombinant follicle-stimulating hormone,gonadotropin releasing hormone antagonists,and human chorionic gonadotropin on endometrial maturation on the day of oocyte pick-up

OBJECTIVE: To assess the effect of ovarian stimulation with recombinant FSH, GnRH antagonists, and hCG on endometrial maturation on the day of oocyte pick-up. DESIGN: Prospective study. SETTING: Tertiary referral center. PATIENT(S): Fifty-five women undergoing controlled ovarian hyperstimulation for IVF/intracytoplasmic sperm injection (ICSI). INTERVENTION(S): [1] Ovarian stimulation with recombinant FSH, starting on day 2 of the cycle and GnRH antagonist, starting after a median of 6 days of recombinant FSH stimulation (range, 5-12 days); [2] hCG administration for ovulation induction; and [3] aspirational biopsy of endometrium at oocyte pick-up. MAIN OUTCOME MEASURE(S): Endometrial histology at oocyte pick-up by Noyes criteria. RESULT(S): Advancement of endometrial maturation (2.5 +/- 0.1 days) as compared to the expected chronological date was observed in all antagonist cycles at oocyte retrieval. Endometrial advancement at oocyte pick-up increased in line with values of LH at initiation of stimulation and the duration of recombinant FSH treatment before the antagonist was started. CONCLUSION(S): The higher the values of LH at initiation of stimulation and the longer the duration of recombinant FSH treatment before the antagonist is started, the more advanced the endometrial maturation at oocyte pick-up.     

Cytotoxic effect of conjugates of doxorubicin and human chorionic gonadotropin (hCG) in breast cancer cells

Cytotoxic activity of drug conjugates of human chorionic gonadotropin (hCG) and doxorubicin alone was investigated compared to doxorubicin in breast cancer cells with and without expression of hCG receptors. Expression of hCG receptor was determined in MCF-7 and MB231 breast cancer cell line using a multiplex nested rt-PCR approach. The entire sequence of mRNA encoding for hCG receptor was detected in MCF-7 but not in MB231 breast cancer cell line. Cytostatic effect of doxorubicin–hCG conjugates was investigated in these cell lines in comparison to unconjugated doxorubicin. The number of viable cells was determined after 24, 48, 72, 96, and 120 h. To exclude non-specific uptake of the carrier hCG from the culture media, a similar experiment was performed with albumin–doxorubicin conjugates. The number of viable cells decreased in a concentration depending manner after doxorubicin and hCG–doxorubicin conjugate treatment. However, the cytotoxic effect of hCG–doxorubicin conjugate was 10-fold increased compared to unconjugated doxorubin in hCG-receptor positive MCF-7 but not in hCG-receptor negative MB231 cells. Albumin–doxorubicin conjugates showed no increased toxicity compared to doxorubicin. We conclude that the cytotoxic effect of hCG–doxorubicin conjugates is mediated specifically via the hCG receptor. By using hCG conjugates, the development of more selective cytostatics can be achieved.     

Validation of 125I-hCG as a marker for elimination of hCG and stability of 125I-hCG after in vivo injection in humans.

We have recently introduced 125I-hCG as an elimination marker in patients with human chorionic gonadotrophin (hCG) producing testicular cancer. 125I-hCG is a well-known reagent in clinical biochemistry and is used extensively in hCG assays. Previous studies have shown that the iodination process leaves the hCG molecule mainly intact. The iodination, purification and stability of 125I-hCG tracer are described. The aim of the present study was to determine whether or not 125I is associated with hCG after the injection of 125I-hCG intravenously (i.v.) in humans. Three different methods were used. Following injection of 125I-hCG, the plasma disappearance of radioactivity and hCG were followed for a period of 28 days in 13 normal subjects. Serum from a normal healthy male following injection of 125I-hCG was analysed using a double antibody direct binding radioimmunoassay specific for holo-hCG and high performance liquid chromatography (HPLC). Following injection of 125I-hCG in eight normal healthy males and five normal healthy females, the disappearance of radioactivity and hCG showed identical paths in the 28 days follow-up period. The bindable radioactive fraction of immunologically active hCG in serum of a normal healthy male following injection of 125I-hCG was between 57.0% and 72.1%, and was constant over time. HPLC showed similar elution pattern of serum from a normal healthy male injected i.v. with 125I-hCG and 125I-hCG. Using three different methods, we were able concurrently to demonstrate the association of 125I with hCG in humans up to 28 days after injection of radiolabelled hCG i.v. Thus, information about the expected elimination of hCG can be obtained by following the elimination of activity in plasma after injection of 125I-hCG.     

Expression and characterization of recombinant β-subunit hCG homodimer

We have linked two human chrionic gonadotropin (hCG) β-subunit cDNAs in tandem such that the expressed fusion protein consists of two mature β-subunits joined through the carboxy terminal peptide of the first β-subunit. A single glycine residue is inserted between the two subunits in the fusion protein. Chinese hamster ovary (CHO) cells transformed with a clone that contains the fused cDNAs express and secrete a protein that is consistent with it being a β-hCG homodimer protein. These β-homodimer molecules can recombine with two free α-subunits indicating that both β-subunits within the homodimer are likely folded in their native conformation. Our data also suggest that the two β-subunits fold upon each other as a globular protein and do not appear to exist as a simple fusion of two linear β-subunits. Further-more, the two β-monomer subunits in the fusion protein form a stable homodimer that can bind and activate the hLH/CG receptor specifically. Recombination of the fusion protein with α-subunits appears to favor an arrangement where two α-subunits combine with a single molecule of the fusion protein. The recombined molecule consists of four subunits and is comparable to two tethered hCG moieties, which constitutes a hCG dimer. This hormone dimer can bind and activate the hLH/CG receptor with an activity approximating that of native hCG.     

The discriminatory zone of beta-hCG for vaginal probes.

Recent developments in both laboratory measurements and ultrasound technology have revolutionized the management of early pregnancy. The discriminatory zone concept is a direct result of these developments. By correlating the serum beta-hCG values to the size of an intrauterine gestational sac, a value can be chosen that corresponds to the threshold of visualization of the sac. If the beta-hCG is above this value, a sac must be seen, and if it is not, aggressive steps should be taken to determine whether the pregnancy is abnormal or ectopic. The discriminatory zone may vary among institutions due to different equipment and assays. Thus, its value should be calculated individually at each institution. A proper discriminatory zone and a management protocol such as the one above can eliminate much of the uncertainty in the management of suspected ectopic and early pregnancies.