Robert E. Canfield

Incidence of early loss of pregnancy.

We studied the risk of early loss of pregnancy by collecting daily urine specimens from 221 healthy women who were attempting to conceive. Urinary concentrations of human chorionic gonadotropin (hCG) were measured for a total of 707 menstrual cycles with use of an immunoradiometric assay that is able to detect hCG levels as low as 0.01 ng per milliliter, with virtually 100 percent specificity for hCG in the presence of luteinizing hormone. Our criterion for early pregnancy--an hCG level above 0.025 ng per milliliter on three consecutive days--was determined after we compared the hCG levels in the study group with the levels in a comparable group of 28 women who had undergone sterilization by tubal ligation. We identified 198 pregnancies by an increase in the hCG level near the expected time of implantation. Of these, 22 percent ended before pregnancy was detected clinically. Most of these early pregnancy losses would not have been detectable by the less sensitive assays for hCG used in earlier studies. The total rate of pregnancy loss after implantation, including clinically recognized spontaneous abortions, was 31 percent. Most of the 40 women with unrecognized early pregnancy losses had normal fertility, since 95 percent of them subsequently became clinically pregnant within two years.

Effects of Dichloromethylene Diphosphonate on Skeletal Mobilization of Calcium in Multiple Myeloma

Dichloromethylene diphosphonate (Cl2MDP), an inhibitor of oestoclast activity, was evaluated for its ability to decrease the excessive mobilization of skeletal calcium that complicates multiple myeloma. Ten patients with active myeloma, wide-spread bone disease, and hypercalciuria were studied in a double-blind, placebo-controlled, crossover-designed trial in which they took Cl2MDP for eight weeks and placebos for eight weeks. Two patients died during the placebo phase; of eight patients who received Cl2MDP, seven had rapid, sustained, and highly significant (P less than 0.001) decreases in urinary excretion of calcium. Six also had significant decreases in hydroxyproline excretion, and five reported lessening of skeletal pain. On patient did not respond. Although the patients received concurrent chemotherapy during the study, concentrations of myeloma proteins actually increased or decreased only slightly, indicating the declines in hypercalciuria resulted from Cl2MDP and not from improvement in the underlying disease. We conclude that Cl2MDP is a potentially useful inhibitor of osteoclast-mediated bone erosion in multiple myeloma.

Measuring early pregnancy loss: laboratory and field methods *

We intensively studied 30 women attempting pregnancy in order to lay groundwork for larger studies of early pregnancy loss. These women collected first morning urine specimens for up to 6 months after discontinuing use of birth control. Urine specimens were successfully collected for 98% of the woman-days in the study. Three assays for human chorionic gonadotropin (hCG) were performed on each urine specimen. An immunoradiometric assay (IRMA) specific to the carboxyterminal peptide of the hCG beta-chain proved to be more sensitive and more specific than two radioimmunoassays (RIAs). Using the IRMA, we found four cases in which hCG rose and fell over successive days, consistent with early pregnancy loss. For three of these four cases, the level of hCG was too low to be detectable with the RIAs. Among the control group of five women with tubal ligations, there was no detectable hCG above threshold with the IRMA. Thus, the enhanced sensitivity and specificity of the IRMA allows very early pregnancy losses to be identified that would otherwise be undetectable. Furthermore, its effectiveness with small quantities of first morning urine makes the IRMA a useful tool for epidemiologic studies.

Hypercalcemia of Malignancy: Treatment with Intravenous Dichloromethylene Diphosphonate

Twelve patients with hypercalcemia associated with various malignancies were treated with intravenous dichloromethylene diphosphonate (Cl2MDP), a potent inhibitor of osteoclastic bone resorption, in doses of 2.5 mg/kg of body weight initially and 5.0 mg/kg thereafter for up to 7 days. Mean serum calcium concentration fell from 13.8 +/- 0.6 mg/dL (SEM) before Cl2MDP to 9.8 +/- 0.7 mg/dL (SEM) (p less than 0.001) after 7 days. Urine calcium excretion fell from 775 +/- 95 mg/g creatinine (SEM) to 272 +/- 70 mg/g creatinine (SEM) (p less than 0.005), and urine hydroxyproline excretion fell from 144 +/- 28 mg/g creatinine (SEM) to 78 +/- 18 mg/g creatinine (SEM) (p less than 0.05) after treatment with Cl2MDP. The Cl2MDP was well tolerated, and adverse effects were limited to asymptomatic hypocalcemia in two patients. The ability of Cl2MDP to correct hypercalcemia and reduce urine calcium and hydroxyproline excretion in these patients is consistent with the hypothesis that increased bone resorption is primarily responsible for this complication of malignancy and suggests that Cl2MDP may be highly useful in managing this condition.

Studies of Human Chorionic Gonadotropin

Publisher Summary This chapter focuses on human chorionic gonadotropin (HCG), a glycoprotein hormone produced by the placenta that appears in significant quantities in the urine during the first trimester of pregnancy. The mean level of urinary HCG produced during the first trimester is 30,000–50,000 IU in 24 hours, equivalent to a maximum of approximately 3 mg of hormone. The high proline content is of particular interest because proline is an uncommon amino acid in most proteins and only collagen appears to have a higher content than HCG. Equilibrium sedimentation studies of reduced, alkylated HCG in the ultracentrifuge indicated that the molecular weight value had fallen to approximately one-half of that of the native hormone. Interchange of the HCG subunits with other molecules might lead to the appearance of different substances possessing other biological activities. Another possibility is that the pooled urinary material from which the HCG was purified was contaminated with a significant quantity of postmenopausal urine.

Development and characterization of antibodies to a nicked and hyperglycosylated form of hCG from a choriocarcinoma patient: generation of antibodies that differentiate between pregnancy hCG and choriocarcinoma hCG.

Human chorionic gonadotropin (hCG) exists in blood and urine as a variety of isoforms one of which contains peptide bond cleavages within its β-subunit loop 2 and is referred to as nicked hCG (hCGn). This hCG isoform appears to be more prevalent in the urine of patients with certain malignancies and possibly in some disorders of pregnancy. Until now, only indirect immunoassays could be used to quantify hCGn. We report the development of two monoclonal antibodies (MAbs) to a form of hCGn isolated from a choriocarcinoma patient. This hCG isoform was not only 100% nicked, but also contained 100% tetrasaccharide-core O-linked carbohydrate moieties in its β COOH-terminal region. Two-site immunometric assays have been developedusing these new antibodies, B151 and B152. The former exhibits good specificity for hCGn independent of the source of the hCGn, the form excreted by choriocarcinoma patients or the form of hCGn from normal pregnancies. The latter antibody, B152, is sensitive to the carbohydrate moieties and possibly other differences in hCG isoforms, but is not for nicking of the β-subunit. These two immunometric assays provide potential novel diagnostic tools for direct measurement of hCG isoforms which could not be accurately quantified earlier before development of the assays using these newly generated antibodies.

Evidence that chorionic gonadotropin has intrinsic thyrotropic activity

Summary The thyrotropic and gonadotropic specific biologic activities of chorionic gonadotropin (hCG) as assessed by the mouse thyrotropin and prostate weight bioassays increased at least 5 fold during purification. The hCG generated from recombination of hCG subunits that were essentially devoid of both activities recovered thyrotropic as well as gonadotropic biologic activity. These data show that the substance with thyrotropic activity found in hCG preparations has physicochemical properties indistinguishable from those of hCG and therefore, these results strongly suggest that thyrotropic activity is an intrinsic property of hCG.

Effects of dichloromethylene diphosphonate in women with breast carcinoma metastatic to the skeleton

Ten women with skeletal metastases from breast carcinoma received dichloromethylene diphosphonate (Cl2MDP), an inhibitor of osteoclast function, in a placebo-controlled, double-blind, crossover study. Eight of these patients had either hypercalcemia or hypercalciuria, and all 10 had elevated urinary hydroxyproline levels as evidence of active skeletal disease. Eight patients had moderate to severe bone pain. After eight weeks of oral dichloromethylene diphosphonate treatment (3,200 mg per day), either preceded by or followed by an eight-week placebo period, seven of eight patients with hypercalciuria had significant reductions in urinary calcium levels, and nine of 10 had reductions in urinary hydroxyproline levels (significant in eight) when the dichloromethylene diphosphonate treatment periods were compared with prestudy or placebo periods. Additionally, seven of eight subjects had decreased pain with dichloromethylene diphosphonate. There were no adverse effects other than transient diarrhea in some patients. We conclude that oral dichloromethylene diphosphonate can significantly inhibit osteoclast-mediated bone destruction in patients with bone metastases from breast cancer.

Giant cell tumor in Paget's disease of bone: familial and geographic clustering.

Four patients with benign giant cell tumor and one patient with probable benign giant cell tumor associated with Pagets disease of bone are reported. The familial and geographic clustering of these cases is unique in that three patients were related and all patients traced ancestral roots to the same area of southern Italy. Tumors arose from the cranial or facial bones in three patients and from vertebral bodies in two patients. All caused symptoms by local compression, and treatment by curettage or radiotherapy was successful in all patients. Three separate tumors in one patient shrank dramatically in response to treatment with high doses of dexamethasone, and one patient whose tumor caused spinal cord compression showed marked improvement in neurologic function on therapy with dexamethasone. Cancer 44:742‐747, 1979.

Partial amino acid sequence of human placental lactogen precursor and its mature hormone form produced by membrane-associated enzyme activity

Abstract The precursor form of human placental lactogen, synthesized by a wheat germ extract cell-free system, has been partially sequenced and found to contain a high percentage of leucine residues within its first 20 amino acids. The partial NH 2 -terminal structure appears to be: The precursor form of hPL, produced by an ascites extract cell-free system, was cleaved by a membrane-associated enzyme into a form which exhibits the methionine and valine residues in NH 2 -terminal positions identical to those of native human placental lactogen.