Brij B. Saxena

Feasibility of maintaining normal glucose profiles in insulin-dependent pregnant diabetic women.

This study was designed to test the feasibility of a patient-monitored glucose determination program to establish and maintain normal blood glucose levels. Ten pregnant women, who were insulin-dependent diabetics prior to becoming pregnant and who were in their eighth week or less of pregnancy, were offered the program. All 10 accepted and continued the program for the duration of their pregnancy. Normal plasma glucose (60 to 140; mean = 80 mg/dl) levels were achieved after one week of the program and were maintained throughout the pregnancy as documented by 5 to 8 blood glucose determinations a day. The hemoglobin A1c level, which was elevated in all 10 patients at the start (9.4 +/- 1.6 per cent) of the program, fell into the normal range (2 to 5.0 per cent) five weeks after glucose values became normal. Serum estradiol (0.8 +/- 0.6 ng/ml), serum prolactin (10 +/- 9 ng/ml) and serum human chorionic gonadotropin (5,500 +/- 1,700 ng/ml), although all abnormal at the start of the program, became normal after glucose control was achieved (program weeks 4, 5 and 6, respectively). The infants showed no signs of macrosomnia (2,988 +/- 959 g), hypoglycemia, hyperbilirubinemia, hypocalcemia, erythremia or respiratory distress. Therefore, a program to maintain normal blood glucose levels during a diabetic patients pregnancy is not only possible but may also improve the pregnancy and the outcome.

The use of a radioreceptorassay of human chorionic gonadotropin for the diagnosis and management of ectopic pregnancy.

The radioreceptorassay of human chorionic gonadotropin (hCG), with a sensitivity of 50 pg or 3 mIU/ml of plasma, has provided almost 100% reliability in detecting pregnancy after the first missed cycle. This test may be performed within 1 hour and is ideally suited to the clinical detection of ectopic pregnancy, especially in patients who require immediate surgical intervention. Thirteen patients with suspected ectopic pregnancy were evaluated by the radioreceptorassay, one of whom was followed with four separate determinations. The results of the assay were subsequently compared with those of hemagglutination pregnancy tests, clinical symptoms, and pathologic findings. All of the patients were diagnosed accurately by the radioreceptorassay, even when hemagglutination tests yielded a false indication of pregnancy. By this assay, the hCG levels during ectopic pregnancies are generally lower than those found during a normal intrauterine pregnancy; in addition, pregnancy may be detected much earlier (prior to the rupture) than is possible by hemagglutination tests. Furthermore, the diagnosis of ectopic pregnancy may be excluded for patients admitted to the hospital with acute abdominal emergencies.

Sustained release of microbicides by newly engineered vaginal rings.

Objective:An effective vaginal microbicide against sexual HIV transmission remains elusive, with requirements for adherence to appropriate application of effective, nontoxic products being a major deterrent. We explored methods to enable sustained release of combinations of antiretroviral microbicides, utilizing intravaginal rings composed of biosoluble Acacia gum or nonbiodegradable hydrogel of 2-hydroxyethyl methacrylate and sodium methacrylate, materials approved for use by the US Food and Drug Administration. Design and methods:The reverse transcriptase inhibitors TMC120, PMPA, 3′-azido-3′-deoxythymidine, and a newly characterized anti-HIV agent, Boc-lysinated betulonic acid, were incorporated into vaginal rings with different combinations. Daily and cumulative release rates of these inhibitors in ring eluates were determined by high-performance liquid chromatography, gas chromatography, or immunoassay. Anti-HIV effects were measured by assessment of p24 Gag antigen in T-cell cultures exposed to HIV-1 isolates. Results:Drug release rates were sustained at concentrations higher than the minimum effective dose for HIV inhibition. The release was maintained for no less than 15 and 28 days from the Acacia gum and 2-hydroxyethyl methacrylate and sodium methacrylate rings, respectively. Boc-lysinated betulonic acid showed more than 90% inhibition of HIV-1 infection in H9 cells, with little toxicity to normal cells. Conclusion:The intravaginal rings described here are capable of efficacious drug delivery. Incorporation of several antiretroviral agents, including betulinol derivatives, which act at multiple levels of the HIV life cycle, may provide a synergistic effect to achieve higher efficacy on the inhibition of HIV infection.

Gonadotropin receptors in the plasma membrabes of rat luteal cells

Abstract 1. 1. In in vivo studies, human chorionic gonadotropin (HCG) labeled with 131I was concentrated by the ovaries of the normal and superovulated rats, whereas 131I-labeled bovine serum albumin and 131I were not incorporated. The distribution of 131I-labeled HCG was examined in the subcellular fractions of the ovaries. Injection of unlabeled HCG or HCG-antisera decreased the uptake of 131I-labeled HCG by mitochondrial and microsomal fractions suggested that the HCG entered the luteal cells. 2. 2. In in vitro studies, the 125I-labeled HCG bound to plasma membranes decreased proportionately to the increasing amounts of unlabeled HCG. Unlabeled human luteinizing hormone also decreased the uptake of 125I-labeled HCG by the plasma membranes, however to a lesser degree than the unlabeled HCG. The plasma membranes did not bind 131I-labeled bovine serum albumin or 131I. The uptake of 125I-labeled HCG by the plasma membranes was not decreased by human follicle-stimulating hormone, subunits of human follicle-stimulating hormone, HCG and human luteinizing hormone, ovine prolactin and human growth hormone, suggesting the presence of specific receptors for HCG in the plasma membranes of rat luteal cells. The mitochondrial and microsomal fractions bound both labeled HCG as well as labeled bovine serum albumin. The presence of unlabeled HCG did not decrease the uptake of 131I-labeled HCG by mitochondrial and microsomal fractions. 3. 3. In in vitro studies, the binding of 125I-labeled HCG to plasma membranes was maximum at pH 7.0. Binding of labeled HCG to the plasma membranes was rapid at both 4 and 38 °C. Approximately 1.8 · 10−14 moles of 125I-labeled HCG saturated receptor sites in 1 mg of plasma membrane protein. Incubation of plasma membranes saturated with 125I-labeled HCG in a hormone-free medium showed a dissociation of 125I-labeled HCG from the plasma membranes which was significantly greater at 38 °C than at 4 °C. At 38 °C the rate of association was 1.0 · 108 moles−1 · s−1 and the rate of dissociation was 1.7 · 10−4 · s−1. The association and dissociation constants obtained from the ratio of rate constants were 6.5 · 1011 M−1 and 1.5 · 10−12, respectively. Increasing salt concentration to 0.5 M NaCl and treatment with phospholipase C resulted in an increase in binding of 125I-labeled HCG to the plasma membranes. Temperature of 95 °C and treatment of plasma membranes with chloroform-methanol (2:1, v/v) abolished hormone-receptor binding due to denaturation of proteinsas well as delipidization. 4. 4. In in vivo experiments, HCG and human luteinizing hormone injected into superovulated rats stimulated adenylate cyclase activity in ovarian homogenates. The subunits of HCG and human luteinizing hormone, on the other hand, were significantly less potent in stimulating adenylate cyclase activity. Injection of HCG, human luteinizing hormone and their α- and β-subunits in superovulated rats did not show increase in the progesterone levels of the ovarian homogenates; however, the progesterone levels in peripheral plasma were significantly elevated. These observations indicate that the action of native hormones on the ovaries was mediated via a specific receptor in the plasma membranes and membrane-bound adenylate cyclase of the luteal cells, whereas subunits act via a different receptor or pathway, without mediation via membrane-bound adenylate cyclase.

Plasma testosterone and dihydrotestosterone in ovulatory and anovulatory cycles

Daily plasma testosterone (T) and dihydrotestosterone (DHT) as well as plasma lueteinizing hormone, plasma estradiol (E2) and plasma progestrone (P) were measured by radioimmunoassay in seven ovulatory cycles and in three anovulatory cycles. In ovulatory cycles, plasma T ranged from 110 to 637 pg. per milliliter, while plasma DNT ranged from 10 to 246 pg. per milliliter. There is an increase in the mean plasma T during the early follicular phase of the cycle with a fall on the day of ovulation. Plasma T levels rise again during the early luteal phase and drop during the late luteal phase of the cycle. Plasma E2 rises during the follicular phase with a preovulatory surge followed by a drop after ovulation and a subsequent secondary rise. Plasma P was less than 1 ng. per milliliter during the follicular phase and increased to above 5 ng. per milliliter after ovulation, reaching levels of 20 to 25 ng. per milliliter during the luteal phase. In anovulatory cycles, there is random fluctuation with no well-defined patterns. Plasma P remained below 1 ng. per milliliter throughout the cycle. The finding of maximum T levels prior to midcycle may reflect increased T production by the ovaries in response to increasing levels of follicle-stimulating hormone. There is little fluctuation in the levels of T during the menstrual cycle. These findings obviate the need for multiple plasma T estimations in the assessment of women with hirsutism, polycystic ovarian disease, and the testicular feminization syndrome.

Studies on the disulfide bonds in human pituitary follicle-stimulating hormone

Human follicle-stimulating hormone (FSH) was digested with subtilisin, thermolysin, cyanogen gromide, pronase and trypsin to isolate the cystine-containing peptides. These peptides were purified by gel filtration through Sephadex G-50 column and by high-voltage paper electrophoresis at pH 6, 3.5 and/or 2. The location of the cystine-containing peptides in human FSH alpha- and beta-subunits was established by amino acid composition, end-group analysis and determination of the amino acid sequence by Edman degradation. The results indicate that the disulfide bonds are present between half-cystine residues located between positions 7 and 10, 28 and 87 and 82 and 84 in the alpha-subunit, and between positions 3 and 28, 17 and 51 and 32 and 104 in the beta-subunit of human FSH.

Application of a Radioreceptorassay of Human Chorionic Gonadotropin in the Diagnosis of Early Abortion

A radioreceptorassay for human chorionic gonadotropin (hCG) was used to detect pregnancy as early as 6 to 8 days following conception and to predict spontaneous abortion as early as 8 to 10 days after conception in subjects whose hCG levels were lower than those occurring during normal pregnancy of the same duration. The evidence for the specific measurement of hCG was further provided by the correlation of plasma hCG levels measured by radioimmunoassay using antisera specific for hCG-beta and radioreceptorassay of hCG. By virtue of its sensitivity and specificity, the radioreceptorassay of hCG allowed early and accurate prediction of spontaneous abortion in 15 patients.

Effect of Daily Administration of 0.5 Mg. of Chlormadinone Acetate on Plasma Levels of Follicle-Stimulating Hormone, Luteinizing Hormone, and Progesterone During the Menstrual Cycle *

Investigators at Cornell University Medical College and New York Medical College in New York City studied the effects of chlormadinone acetate administration on hormone levels in an effort to better understand the contraceptive mode of action of this drug. 9 healthy women had 2 consecutive cycles studied. While the first cycle was a control cycle, the second one involved chlormadinone acetate administration, .5 mg/day from Day 1 to Day 28 or until the occurrence of spontaneous menstruation if this delayed until after Day 28. Basal body temperature was recorded each morning. Chlormadinone tended to suppress the mean luteinizing hormone and follicle stimulating hormone peaks and the plasma progesterone levels. 3 patients are believed to have ovulated during the experimental cycle, but probably in 2 of them the luteal phase was less pronounced than a normal luteal phase. However, 1 of the remaining 6 patients had failed to ovulate in the control cycle. Though limitations exist in the study of the parameters investigated here, such study is necessary since direct evidence of ovulation (e.g., pregnancy, observation of corpus luteum) is usually unobtainable.

Clinical validation of enzymeimmunoassay of human luteinizing hormone (hLH) in the detection of the preovulatory luteinizing hormone (LH) surge in urine

The preovulatory luteinizing hormone (LH) surge (mean, 60.7 standard error +/- 4.7 mIU/ml) as determined by a solid-phase enzymeimmunoassay in urine has been correlated with clinical parameters in 24 women. In group A, of seven women, the preovulatory LH surge correlated with basal body temperature and cervical mucus. In one of the women in group A, serum levels of pituitary and gonadal hormones confirmed ovulation. In group B, of 17 women, the urinary estrone-3-glucuronide (E1-3-G) peak was either coincident with or preceded the LH surge. The LH surge in all cases occurred 12 to 24 hours prior to follicular rupture, as visualized by real-time sonography. The enzymeimmunoassay for the detection of the preovulatory LH surge is useful in patients for artificial insemination and for aspiration of mature oocytes for in vitro fertilization.

Verification of Early Pregnancy Tests in a Multicenter Trial

Abstract Tests for the diagnosis of early pregnancy have been available since 1974. However, no studies have systematically verified the accuracy of routine clinical laboratories in measuring human chorionic gonadotropin (hCG) prior to the time that pregnancy is clinically evident. We have conducted such a study in association with the NICHD-funded Diabetes in Early Pregnancy Study (DIEP). The purpose of this study was to elucidate the etiology of malformations in pregnancies complicated by diabetes mellitus, which probably occurs within the first few weeks of pregnancy, and therefore uniformity of pregnancy testing was necessary among the five centers to find an association of a teratogen at the time of organogenesis. We confirmed that routine clinical laboratories, in fact, could measure accurately hCG at the time of the missed menses; however, detection was not necessarily possible prior to that time. We conclude that in order to assure accurate diagnosis of early pregnancy, tests should ordinarily be delayed until time of the missed menses. When the test is used at this time, it is a reliable tool for early pregnancy testing and thus can be used to resolve questions relating to early pregnancy pathophysiology.