PubMed Health⌕ Search

Biomedical subjects

B B Saxena

Publications and source records attributed to B B Saxena.

At least 37 records · Page 2Linked to original sources

Contraceptive efficacy of bioabsorbable pellets of norethindrone (NET) as subcutaneous implants: phase II clinical study.

The contraceptive efficacy of norethindrone (NET) fused pellets was evaluated over 12 months in a Phase II clinical study with three and four pellets, each pellet containing 35 mg of NET. Volunteers were healthy, fertile, sexually active women. The release rate of NET from three and four pellets, respectively, was 150.3 +/- 7.2 micrograms and 212.5 +/- 8.6 micrograms NET/day. Following the implantation of NET pellets, serum NET levels did not show any 'burst effect' and were sustained at levels between 0.4 and 0.6 ng NET/ml serum with three pellets and 0.6-0.7 ng NET/ml serum with four pellets. With three and four pellets, respectively, 40% and 27% of the women had normal menstrual cycles; 20% and 14% were amenorrheic; 27% and 37% had mid-menstrual spotting or bleeding; and 13% and 22% had prolonged episodes of bleeding. Cardiovascular, hepatic, and renal functions were normal throughout the study. Ovulation was inhibited in 85% and 92% of the cycles with three and four pellets, respectively. In women using three pellets, two pregnancies occurred, one at the 6th cycle and another at the 12th cycle. In women using four pellets, no pregnancies occurred during the entire period of study.

Adult↗

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.

Adult↗

A "sandwich" solid-phase enzyme immunoassay for lutropin in urine.

In this "sandwich" technique of enzyme immunoassay for lutropin in urine, a highly purified lutropin-specific anti-gamma-globulin is conjugated with alkaline phosphatase. The conjugate is then extensively purified to remove free enzyme and free antibody molecules. The solid phase consists of anti-lutropin immune globulin coupled to polystyrene tubes or beads. The specific antibody on the solid phase binds the lutropin in the urine sample or in the standard solution, which in turn binds to the specific antibody conjugated to the enzyme. The amount of bound enzyme, which is determined colorimetrically, is thus directly proportional to the amount of lutropin in the sample. We optimized assay conditions and report them here. The sensitivity of the assay is equal to that of radioimmunoassay and almost 10-fold that of the hemagglutination inhibition assay. The test can be used to detect the pre-ovulatory surge of lutropin in women.

Animals↗

Subcutaneous bioabsorbable pellets of norethindrone for contraception in women: Phase I. Clinical study.

Ten healthy, normally menstruating female volunteers participated in a 1-year phase I clinical study in which subcutaneous pellet implants of norethindrone (NET) were employed as a low-dose and long-acting potential contraceptive. Two NET pellets were implanted subcutaneously by the aid of a trocar in the forearm of each volunteer on the fifth day after the start of menstrual bleeding. Serum levels of NET, follicle-stimulating hormone, luteinizing hormone, 17 beta-estradiol, and progesterone were determined weekly by radioimmunoassay. The daily NET release from the pellets, based on mean values (+/- standard error of the mean) in five subjects was 79.4 +/- 7.6 micrograms. The mean serum NET level was initially 1.0 +/- 0.34 ng/ml; thereafter, it gradually lowered during the 343 days of the study period to the level of 0.43 +/- 0.09 ng/ml. The ovarian response, days of bleeding, and cycle lengths with continuously sustained release of NET from the pellets were similar to those observed in women taking the daily oral "minipill" of 300 micrograms NET. The results of the phase I study suggest that NET pellet implants may provide a simple and acceptable approach to long-term contraception in women.

Absorption↗

Enzyme assays to detect preovulatory human luteinizing hormone surge.

Nonradioisotopic enzyme assays have been developed to detect the preovulatory luteinizing hormone (LH) surge in the unextracted urine of normally menstruating women. The amino groups on 6-mm glass beads were activated and coupled to the anti-LH-gamma-globulin for enzyme immunoassay or to the LH receptor prepared from bovine corpora lutea for enzyme receptorassay. The LH was conjugated with alkaline phosphatase. The enzyme assays detected preovulatory LH surge in the morning urine samples of 12 normally menstruating women. The LH surge was coincidental with preovulatory serum estradiol rise, shift in basal body temperature, and 4+ spinnbarkeit of the cervical mucus. The serum estradiol and progesterone levels in the luteal phase were indicative of corpus luteum formation.

Adult↗

Purification and properties of human chorionic gonadotropin/lutropin receptor from plasma-membrane and soluble fractions of bovine corpora lutea.

Plasma-membrane and soluble fractions containing human chorionic gonadotropin/lutropin receptor were prepared from bovine corpora lutea by ultracentrifugation. The plasma-membrane and soluble fractions were studied for physicochemical properties, salts and gangliosides. The receptor preparations obtained from the plasma-membrane purified individually by sucrose-density-gradient centrifugation, which resulted in a partial dissociation of the hormone-binding subunit from the intact functional receptor unit, which consists of both hormone-binding (regulatory) and adenylate cyclase-associated (catalytic) subunits. The fractions containing the functional receptor unit were further purified by gel filtration on Sepharose-6B and chromatography on concanavalin A-Sepharose. The 'receptor' was finally purified by affinity chromatography on a column of controlled-pore glass covalently coupled to hu man chorionic gonadotropin. The purified receptor from the plasma-membrane and the soluble fractions contained binding capacities of 901000 and 87000 fmol of human chorionic gonadotropin/mg of protein. Yields of 0.02 and 0.22mg of protein were obtained from 250 g of bovine corpora lutea, which represents a 10000- and 1000-fold increase respectively in the specific binding with 125I-labelled human chorionic gonadotropin. Immunization of rabbits with a partially purified receptor fraction generated antibodies that specifically inhibited the binding of the 125I-labelled human chorionic gonadotropin to the receptor.

Animals↗

Steroid hormone secretion from a virilizing lipoid cell tumor of the ovary.

The authors report the case of a 23-year-old woman with a virilizing lipoid cell tumor of the ovary. The patient developed precocious puberty at age 4 and from age 5 to 10 years was treated weekly with intramuscular medroxyprogesterone acetate. She began to menstruate spontaneously at age 13, but developed hirsutism, acne, and irregular menses at age 15 followed by secondary amenorrhea at age 20. Steroid analyses demonstrated elevated peripheral plasma levels of testosterone, dihydrotestosterone, androstenedione, 17 alpha-hydroxyprogesterone, progesterone, desoxycorticosterone, estrone, and estradiol. Catheterization of the adrenal and ovarian veins revealed increased secretion of testosterone, dehydroepiandrosterone, androstenedione, 17 alpha-hydroxyprogesterone, progesterone, desoxycortcosterone, and corticosterone, 11-desoxycortisol, cortisol, estrone, and estradiol from the right ovarian vein. At surgery a right ovarian lipoid cell tumor was removed. Incubation studies with the tumor tissue confirmed the presence of gonadal and adrenocortical steroids. The tissue also contained high-affinity human chorionic gonadotropin-luteinizing hormone binding sites with normal binding affinity.

Adrenal Cortex Hormones↗

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.

Animals↗

Conjugation of a fetuin glycopeptide to human follicle-stimulating hormone and its subunits by photoactivation.

Human follicle-stimulating hormone (human FSH), dansylated human FSH, human FSH-alpha and human FSH-beta subunits were individually conjugated by photoactivation to an azidobenzoyl derivative of a glycopeptide isolated from fetuin. The conjugates were purified on a column of Sephadex G-100. The carbohydrate content of the conjugated human FSH increased 2.7-fold with a concomitant 1.5- and 2-fold increase in the immunological and biological activity of the human FSH. The glucosamine content of the human FSH-alpha and human FSH-beta increased 6- and 1.4-fold, respectively, after conjugation. Human FSH-alpha conjugate, when recombined with untreated human FSH-beta showed up to 50% increase in the biological activity over the control. When the conjugated human FSH-beta was combined with untreated human FSH-alpha, there was little change in the biological activity. These experiments demonstrate that the photoactivation procedure, although random and site-nonspecific in nature, provides a potential means of attachment of glycopeptides to the protein moiety and enhancement of the hormonal activity of human FSH.

Carbohydrate Conformation↗

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 patient's pregnancy is not only possible but may also improve the pregnancy and the outcome.

Adult↗