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Biomedical subjects

A M Bongiovanni

Publications and source records attributed to A M Bongiovanni.

At least 19 recordsLinked to original sources
PubMed1990

Characterization of cytosolic glucocorticoid receptor of fetal rat epiphyseal chondrocytes.

The cytosolic glucocorticoid receptor of 21st gestational day rat epiphyseal chondrocytes has been evaluated. The receptor, a single class of glucocorticoid binding component approached saturation, utilizing [3H]triamcinolone acetonide ([3H]TA) as the radiolabeled ligand, at approximately 1.8-2.0 x 10(-8) M. The dissociation constant (Kd) reflected high-affinity binding, equaling 4.0 +/- 1.43 x 10(-9) M (n = 7) for [3H]TA. The concentration of receptor estimated from Scatchard analysis was approximately 250 fmol/mg cytosolic protein and when calculated on a sites/cell basis equalled 5800 sites/cell. The relative binding affinities of steroid for receptor were found to be triamcinolone acetonide greater than corticosterone greater than hydrocortisone greater than progesterone greater than medroxyprogesterone acetate much greater than 17 alpha-hydroxyprogesterone much greater than testosterone greater than 17 beta-estradiol. Cytosolic preparations activated in vitro by warming (25 degrees C for 20 min) were shown to exhibit an increased affinity for DNA-cellulose. 46% of the total specifically bound activated ligand-receptor complex was bound to DNA-cellulose. Cytosol maintained at 0-4 degrees C in the presence of 10 mM molybdate or activated in vitro in the presence of molybdate, bound to DNA-cellulose at 8 and 10% respectively. DEAE-Sephadex elution profiles of the nonactivated receptor were indicative of a single binding moiety which eluted from the columns at 0.4 M KCl. Elution profiles of activated receptor were suggestive of an activation induced receptor lability. The 0.4 M KCl peak was diminished, while a concomitant increase in the 0.2 M KCl peak was only modestly discernible. Evaluation of endogenous proteolytic activity in chondrocyte cytosol using [methyl-14C]casein as substrate show a temperature-dependent proteolytic activity with a pH optimum of 5.9-6.65. The proteolytic activity was susceptible to heat inactivation and was inhibitable, by 20 mM EDTA. The sedimentation coefficient of the nonactivated receptor was 9.3s (n = 6) on sucrose density gradients and exhibited steroid specificity and a resistance to activation induced molecular alterations when incubated in the presence of 10 mM molybdate. Receptor activation in vitro, in the absence of molybdate induced an increased receptor susceptibility to proteolytic attack and/or enhanced ligand receptor dissociation as evidenced by a diminution of the 9.3s binding form without a concomitant increase in 5s or 3s receptor fragments.

Animals↗
PubMed1987

Are ovarian steroids required for ovum maturation and fertilization? Effects of cyanoketone on the in vitro perfused rabbit ovary.

An isolated perfused rabbit ovary preparation was used to determine the effects of cyanoketone, a potent inhibitor of 3 beta-hydroxysteroid dehydrogenase, on ovulation, ovum maturation and fertilizability, and steroid production. In the first experiment, cyanoketone (10(-4) M) was added to the perfusate of one ovary. The contralateral control ovary was perfused with medium alone. Thirty minutes after the onset of perfusion, hCG (50 IU) was added to the perfusate of both ovaries. The ovulatory efficiency of ovaries treated with cyanoketone plus hCG (82.3 +/- 4.6%) was similar to that of ovaries treated with hCG alone (84.8 +/- 4.4%). No difference was observed in the degree of ovum maturity or degeneration between control and cyanoketone-treated ovaries. Progesterone and estradiol production were significantly reduced by cyanoketone treatment; concentrations in the perfusate of ovaries treated with cyanoketone were 9.7% and 8.0% of the control values, respectively, 2 h after exposure to hCG. The concentration of 17-hydroxypregnenolone was not affected by cyanoketone treatment. Exposure to cyanoketone resulted in a significant (P less than 0.005) reduction in the fertilizability of ova ovulated and fertilized in vitro. In the second experiment, the percentage of ova that showed evidence of normal fertilization was significantly (P less than 0.025) increased in ovaries perfused with cyanoketone plus estradiol (64.5%) compared to that in ovaries perfused with cyanoketone alone (32.4%). In the third experiment, the addition of progesterone to the perfusate did not affect fertilizability of ovulated ova in ovaries perfused with cyanoketone plus estradiol. These results suggest that the presence of estradiol in the ovarian steroid environment may be essential for fertilizability of ova, but not for the processes of ovulation or meiotic maturation.

3-Hydroxysteroid Dehydrogenases↗
PubMed1986

The effect of ovarian steroidogenesis on ovulation and fertilizability in the in vitro perfused rabbit ovary.

The effects of aminoglutethimide phosphate (AGP) on ovulation, ovum maturation, fertilizability, and steroid production were studied with the use of an isolated perfused rabbit ovary preparation. AGP (10(-3) or 10(-4) M) was added to the perfusate of one ovary. The contralateral control ovary was perfused in medium alone. Thirty minutes later human chorionic gonadotropin (hCG) (50 IU) was added to the perfusate of all ovaries. No difference was observed in time of ovulation or ovulatory efficiency between controls and AGP-treated ovaries. The degree of ovum maturity and degeneration was also comparable in the two groups. Progesterone and estradiol production were significantly reduced by AGP treatment. A second experiment examined fertilizability of ova ovulated in vitro after perfusion with 10(-3) M AGP. AGP significantly reduced the rate of normal fertilization as observed 12 h after insemination. The percentage of inseminated ova with evidence of degeneration was greater in ova from AGP-treated ovaries than in those from controls, however, this difference was not significant. The study indicates that AGP affects neither hCG-induced ovulation nor meiotic resumption; however, fertilizability of ova from ovaries treated with AGP is impaired. These data suggest that the intrafollicular steroid environment may participate in cytoplasmic maturation of ovulated ova.

Aminoglutethimide↗
PubMed1985

Antibodies to the neutral glycolipid asialo ganglio-N-tetraosylceramide: association with gynecologic cancers.

As part of our efforts to define subpopulations at increased risk for gynecologic malignancies, sera from 145 women were obtained prior to diagnosis and analyzed for antibody to asialo ganglio-N-tetraosylceramide. This neutral glycolipid is present on the surface of thymocytes and natural killer cells, and asialo ganglio-N-tetraosylceramide antibody has been shown in animals to block natural killer cell activity and promote tumor cell proliferation. With the use of an enzyme-linked immunosorbent assay and with a value of 2 SD above the mean for healthy women designated as the boundary for a positive response, antibody to asialo ganglio-N-tetraosylceramide was detected in only one of 30 (3%) healthy women, none of 16 pregnant women, none of 18 women with benign masses, and two of 24 (8%) women with microbial infections. All of the above samples that contained antibodies were barely over the 2 SD limit. In marked contrast, 19 of 35 (54%) women with gynecologic malignancies had asialo ganglio-N-tetraosylceramide antibodies, with positive values ranging to greater than 10 SD above the control mean. Asialo ganglio-N-tetraosylceramide antibody was found in six of eight (75%) patients with cervical cancer, five of eight (63%) with endometrial cancer, and seven of 15 (47%) with ovarian cancer. Of the eight patients with Stage I gynecologic cancer at any site, five (62%) had asialo ganglio-N-tetraosylceramide antibodies. Four of 22 (18%) women with Hodgkin's disease also had antibodies, with values just exceeding 2 SD above control levels. The presence of these antibodies may contribute to an impaired immune surveillance system in these women and so increase their susceptibility to malignancy.

Antibodies↗
PubMed1985

An epidemic of precocious development in Puerto Rican children.

An alarming incidence of premature sexual development has been reported in Puerto Rico during the last 7 years. A significant increment of premature thelarche, premature pubarche, prepubertal breast enlargement in boys, and precocious pseudopuberty in girls has been observed throughout the island. Several food specimens analyzed by chromatography and cytosol receptor assay revealed significant levels of estradiol equivalent in some meat samples. We suspect that the early sexual development is caused by exogenous estrogen contamination in the food ingested by the children and by their mothers.

Breast↗
PubMed1984

Detection and characterization of immune complexes in the circulation of infertile women.

The incidence of circulating immune complexes (CICs) was evaluated in sera from 39 female partners of infertile marriages and from 38 fertile women. Fifteen (38%) of the infertile women had CICs, as determined by the Raji cell assay, in levels ranging from 300 to 8000 micrograms/ml; whereas only 1 (3%) of the fertile women displayed CICs (P less than 0.001). Analysis of the CICs from nine of the women following polyethylene glycol precipitation and acid dissociation revealed that four contained C1q and three contained an antigen reactive with rabbit antibody to human spermatozoa. These latter three women all lacked free sperm antibody, as determined by enzyme-linked immunosorbent assay and agglutination. Thus, CICs are not uncommon as a manifestation of infertility in females. Their presence may lead to an underestimation of sperm antibody levels and may be indicative of underlying infection or autoimmunity.

Agglutination Tests↗
PubMed1983

The response of several adrenocortical steroids to the administration of ACTH in hirsute women.

Thirty-three women with hirsutism and oligomenorrhea were stimulated with synthetic adrenocorticotropin, as well as 12 controls. Of these test subjects 20 demonstrated significantly greater rises of serum levels of 3,17-dihydroxy-5-pregnen-20-one as well as dehydroepiandrosterone sulfate suggesting an attenuated deficiency of 3 beta-hydroxysteroid dehydrogenase. Five did not show similar rises of these compounds but revealed significant elevations of 17-hydroxyprogesterone as would be expected in 21-hydroxylase deficiency. None of the subjects were virilized. Eight additional hirsute women were not different than the normals. It appears that a subtle deficiency of 3 beta-hydroxysteroid dehydrogenase may be more common as an explanation of a syndrome resembling polycystic ovarian disease than has been previously recognized.

17-alpha-Hydroxypregnenolone↗
PubMed1978

Familial hypopituitarism with large sella turcica.

We studied endocrine function in three siblings with short stature and enlargement of the sella turcica. Sellar volumes were 5.9, 3.7 and 4.0 standard deviations above age-specific means. Computed tomography or pneumoencephalography showed full sellae without suprasellar extension. Basal thyrotropin levels were low despite hypothyroidism and increments were less than 3 micromicron per milliliter after thyrotropin-releasing hormone injection. Stimulated growth hormone levels were less than 5 ng per milliliter, declining to less than 2 ng per milliliter after thyroxine treatment. Both thyroxine and growth hormone treatments were required for rapid growth. Impaired thyrotropin responses to thyrotropin-releasing hormone distinguish these patients from most cases of idiopathic or familial deficiency of thyrotropin and growth hormone. Persistent deficiency of growth hormone during thyroxine treatment indicates that the defects is not limited to thyrotropin structure or release. The findings are compatible with either familial neoplasia of the anterior pituitary or a regulatory defect promoting anterior pituitary-cell hyperplasia and inhibiting thyrotropin and growth hormone release.

Adolescent↗
PubMed1978

Adrenocortical response to ACTH stimulation in postmature newborns.

Diminished total plasma cortisol levels have been demonstrated in postmature neonates, suggesting that fetal glucocorticoids may be involved in the cause of postmaturity. This hypothesis was tested by adrenocortical stimulation in 32 newborns: 12 were postmature; 12 were postterm, but not postmature; and 8 were normal term neonates. The mean pre- and poststimulation total plasma cortisol levels were 3.9 and 50.9 microgram/100 ml, respectively, for the postmature newborns, 9.7 and 44.0 microgram/100 ml for the postterm, but nonpostmature newborns, and 9.8 and 37.1 microgram/100 ml for the normal term newborns. The differences in the poststimulation rise in plasma cortisol between the postmature and merely postterm infants or between the postterm and normal term infants were not statistically significant. The mean poststimulation cortisol rise in the postmature group exceeded that of the normal term group (P less than 0.05). The adequacy and promptness of response to adrenocortical stimulation eliminate the likelihood of adrenal insufficiency in postmature infants.

Adrenal Cortex↗