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Biomedical subjects

J E Buster

Publications and source records attributed to J E Buster.

At least 37 records · Page 2Linked to original sources
PubMed1996

Single serum progesterone as a screen for ectopic pregnancy: exchanging specificity and sensitivity to obtain optimal test performance.

OBJECTIVE: To investigate the diagnostic accuracy of screening serum P in diagnosis of ectopic pregnancy (EP) and to identify a cutoff value that provides the best compromise between test sensitivity and specificity. DESIGN: Retrospective analysis. SETTING: University hospital. INTERVENTIONS: Observation only. PATIENTS: First trimester pregnant women at risk for EP. MAIN OUTCOME MEASURE: Single P measurements were obtained from 3,674 pregnancies with outcomes defined as EP, viable intrauterine pregnancy (IUP), and spontaneous abortion (SAB). Diagnostic accuracy of the test was analyzed by generating receiver operating characteristic (ROC) curves, which quantify the ability of the test to distinguish EP and SAB from IUP. RESULTS: Diagnostic accuracy for EP versus IUP was 88.7% +/- 0.1% (mean +/- SEM); for SAB versus IUP, 93.8% +/- 0.4%; and for SAB + EP versus IUP, 92.8% +/- 0.4%. Diagnostic accuracy for SAB versus EP was only 39.4% +/- 0.2%. In the interval of 15.0 to 19.9 ng/mL (47.7 to 63.3 nmol/L), P missed 5.3% of the EPs and incorrectly included 84.3% of the viable IUPs; in the interval of 20.0 to 24.9 ng/mL (63.6 to 79.2 nmol/L), sensitivity improved in that only 3.5% of the EPs were missed but 88.8% of viable IUPs were included incorrectly. A cutoff value of > or = 17.5 ng/mL (55.7 nmol/L), the median point of the 15.0 to 19.9 ng/mL (47.7 to 63.3 nmol/L) interval, missed only 35 of 423 (8.3%) total EPs in the study. CONCLUSION: Analysis of ROC curves demonstrates that single serum P has high diagnostic accuracy for differentiating accidents of pregnancy (SAB and EP) from viable IUP, both individually (SAB versus IUP and EP versus IUP) and collectively (SAB + EP versus IUP); it cannot efficiently discriminate SAB versus EP. We conclude that for P > or = 17.5 ng/mL (55.7 nmol/L), patients thought to be at risk for EP may be followed reasonably without ultrasound or further invasive diagnostic studies.

Abortion, Spontaneous↗
PubMed1996

The zona reticularis is the site of biosynthesis of dehydroepiandrosterone and dehydroepiandrosterone sulfate in the adult human adrenal cortex resulting from its low expression of 3 beta-hydroxysteroid dehydrogenase.

Based on indirect evidence, it has often been assumed that the zona reticularis of the adult human adrenal cortex is the source of the adrenal androgens, dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEAS), but direct tests of this concept have been few. Using the techniques of cell culture, Northern blotting, and RIA, we compared the properties of separated adult zonal cells to those of fetal zone cells, a cell type well known to secrete large amounts of DHEA(S) due to its low expression of 3 beta-hydroxysteroid dehydrogenase (3 beta HSD). In nine glands from donors of a wide age range, the zona fasciculata and zona reticularis were separated and dissociated, and the cells were placed in culture. After 5 days, serum was removed by a 24-h period in serum-free defined medium followed by a 24-h exposure to cAMP analogs, with the optional addition of insulin, also in serum-free medium. The separated fasciculata and reticularis cells showed large differences in the DHEA(S)/cortisol (F) production ratios from added pregnenolone precursor, consistent with the synthesis of only F and essentially no DHEA(S) by fasciculata cells and with the synthesis of mostly DHEA(S) with little or no F by both reticularis cells and fetal zone cells. The different patterns of steroidogenesis were accompanied by a much lower level of expression of type II 3 beta HSD in reticularis cells, similar to that in fetal zone cells. In contrast, other genes were similarly regulated in the two adult zones and in the fetal zone by both cAMP and insulin. The levels of messenger ribonucleic acids for 17 alpha-hydroxylase, cholesterol side-chain cleavage enzyme, 21-hydroxylase, and 11 beta-hydroxylase responded to cAMP and insulin in both reticularis cells and fetal zone cells in the same pattern as that previously established in fasciculata cells. The central role of the limited expression of 3 beta HSD in the DHEA(S)-synthesizing property of reticularis cells was established by inhibition of 3 beta HSD in fasciculata cells with trilostane, which caused them to increase their DHEA/F production ratio to a level exceeding even that in fetal zone cells. There did not appear to any age-related changes in gene expression that could account for the large age-related decline in DHEA(S) biosynthesis in humans in either reticularis or fasciculata cells. Thus, the most likely cause of the age-related decline in adrenal androgen biosynthesis is an age-related decline in the number of functional reticularis cells, without a major change in the differentiated properties of the zonal cells as a function of age.

3-Hydroxysteroid Dehydrogenases↗
PubMed1996

Ovarian hyperstimulation augments adrenal dehydroepiandrosterone sulfate secretion.

OBJECTIVE: To determine if factor(s) secreted by the ovaries during hyperstimulation potentiate basal and ACTH-stimulated adrenal androgen secretion. DESIGN: Retrospective and prospective and prospective clinical study. SETTING: University tertiary care center infertility clinic. PARTICIPANTS: Two hundred thirteen hyperstimulation cycles in endocrinologically normal women were identified from 92 patients with ovulatory infertility, aged 25 to 45 years. Further, seven endocrinologically normal infertile women, aged 22 to 37 years, who were undergoing empiric ovarian hyperstimulation for infertility were identified and studied. INTERVENTIONS: In the previously performed cycles, basal and peak serum DHEAS and cortisol (F) levels were assayed and compared with each other and to the extant E2 levels. Additionally, at the baseline and the peak of ovarian hyperstimulation cycles, a standard ACTH test was performed and serum was assayed for DHEAS, DHEA, and F. MAIN OUTCOME MEASURE: Basal and ACTH-stimulated serum DHEAS, DHEA (prospective part only), and F concentrations. Where applicable, mean peak values were generated and compared between the baseline and the peak of stimulation with or without a correction for intrapatient variability in F secretion. RESULTS: Basal serum DHEAS levels rose with ovarian hyperstimulation independent of F. Post-ACTH mean peak value concentrations rose with ovarian hyperstimulation for DHEAS but not DHEA or F. CONCLUSIONS: Ovarian hyperstimulation potentiates basal and ACTH perturbed adrenal DHEAS secretion. This implies the existence of a humoral ovarian factor(s) that mediate this ovarian-adrenal cross-talk.

Adrenocorticotropic Hormone↗
PubMed1995

Ectopic pregnancy: new advances in diagnosis and treatment.

Recent reports affirm that ectopic pregnancy has become a medical rather than a surgical disease. Early diagnosis is the key to effective nonsurgical treatment. Diagnostic algorithms using serum progesterone, serial beta-human chorionic gonadotropin measurements, ultrasound, and office curettage now make definitive diagnosis possible without laparoscopy. Laparoscopic salpingostomy, the surgical gold standard, is an effective therapy but carries surgical complications and is expensive. Systemic variable dose methotrexate produces outcomes close to laparoscopic salpingostomy in similar patients. Single dose systemic methotrexate and intratubal methotrexate appear to be less effective. In many cases, ectopic pregnancies do not meet suitable medical criteria and still require surgery. The challenge today is identifying patients at risk and bringing them into the system during the early first trimester when treatment is simple.

Female↗
PubMed1995

Replacement of dehydroepiandrosterone enhances T-lymphocyte insulin binding in postmenopausal women.

OBJECTIVE: To demonstrate bioavailability of 3 weeks of oral micronized DHEA and to delineate changes induced on insulin sensitivity, morphometric indexes, and lipoprotein profiles. DESIGN: Oral micronized DHEa (50 mg/d) was administered in 3-week treatments to 11 postmenopausal women in a prospective, placebo-controlled, randomized, blinded, crossover trial with an interarm washout. After dose (23 hour) serum DHEA, DHEAS, T, and cortisol levels were measured, as were fasting lipoproteins, oral glucose tolerance tests (OGTT), T-lymphocyte insulin binding and degradation, and urine collagen cross-links. Morphometric changes were determined by hydrostatic weighing. RESULTS: Dehydroepiandrosterone sulfate, DHEA, T, and free T increased up to two times premenopausal levels with treatment. Fasting triglycerides declined; no change in collagen cross-links or morphometric indexes was noted. Oral glucose tolerance test parameters did not change, but both T-lymphocyte insulin binding and degradation increased with DHEA. CONCLUSION: Fifty milligrams per day of oral DHEA gives suprahysiologic androgen levels; 25 mg/d may be more appropriate. Dehydroepiandrosterone enhanced tissue insulin sensitivity and lowered serum triglycerides. Rationale is provided for postmenopausal replacement therapy with this androgen.

Aged↗
PubMed1995

Flow cytometry provides rapid and highly accurate detection of antisperm antibodies.

OBJECTIVE: Immunobead testing (IBT), the current standard for antisperm antibody detection, is time consuming and somewhat subjective. To overcome these limitations and maintain accuracy, we studied an immunofluorescent assay using flow cytometry. DESIGN: A validation study comparing flow cytometry to IBT in the detection of serum antisperm antibodies. SETTING: Flow cytometry laboratory. PATIENTS: Sera from 37 men after vasectomy (test) and sera from 35 fertile men (control). MAIN OUTCOME MEASURE: Test serum with and without immunoglobulin (Ig)G, IgA, and IgM antisperm antibodies as defined by IBT were analyzed by flow cytometry. Sensitivity and specificity of flow cytometry was calculated by defining the IBT as the true result. RESULTS: Flow cytometry identified 22 of 22 sera that were IgG positive (100% sensitivity), 12 of 14 sera that were IgA positive (86% sensitivity), and 4 of 4 sera that were IgM positive (100% sensitivity). Overall, 22 of 37 men were positive for antisperm antibodies. The flow cytometry correctly identified 71 of 71 negative sera (100% specificity). Fluorescence intensity values from the 37 study patients significantly correlated with immunobead binding to the head region and to the entire (more than one) region. CONCLUSIONS: Detection of IgG, IgA, and IgM antisperm antibodies by flow cytometry is highly sensitive and specific. In addition, flow cytometry is able to assess thousands of sperm rapidly and accurately, reducing sampling error and technical time.

Antibodies↗
PubMed1994

Basal follicle stimulating hormone (FSH) predicts response to controlled ovarian hyperstimulation (COH)-intrauterine insemination (IUI) therapy.

PURPOSE: This work investigates the relationship of basal follicle stimulating hormone (FSH) measurements and age to ovarian responsiveness and pregnancy occurrence following controlled ovarian hyperstimulation and intrauterine insemination (COH-IUI). METHOD: Basal FSH was measured retrospectively in sera from infertility patients obtained on cycle day 2, 3, or 4 of a COH-IUI treatment cycle. Basal FSH was then correlated with COH response parameters and treatment outcome in ovulatory (n = 98) and anovulatory (n = 33) patients. Clinical data were collected from retrospective chart review. In the ovulatory group, increasing basal FSH was associated with fewer follicles (P = 0.01) and lower peak estradiol (P = 0.0001). RESULTS: No age related effects were detected in the anovulatory group. Also, there were no pregnancies in this group when basal FSH was > 22.1 mIU/ml. Increasing age in the ovulatory group was associated with fewer follicles (P = 0.0001), lower peak estradiol (P = 0.0001), and fewer pregnancies (P = 0.04). In the anovulatory group, basal FSH did not correlate with follicle numbers or peak estradiol, although more ampoules of hMG were used for stimulation (P = 0.03). CONCLUSIONS: Increasing basal FSH and patient age both correlated inversely with ovarian responsiveness to COH in ovulatory patients. Basal FSH can be used in clinically to identify patients undergoing COH who are unlikely to respond to superovulatory drugs and unlikely to become pregnant.

Adult↗
PubMed1994

Embryo survival after pronuclear microinjection and trophectoderm biopsy.

OBJECTIVE: Our purpose was to compare murine embryo development after pronuclear microinjection of a gene construct, followed by trophectoderm biopsy at the blastocyst state, with development after a single micromanipulation, and with cultured controls. STUDY DESIGN: alpha-Myosin heavy-chain gene sequence was microinjected into the murine embryo pronucleus and cultured to blastocyst. After trophectoderm biopsy the embryos were allowed to re-expand. Re-expanded embryos were transferred to pseudopregnant females; implantation and live birth rates were recorded. In this study group the rates were compared with three control groups of embryos simultaneously cultured after (1) pronuclear microinjection only, (2) trophectoderm biopsy only, and (3) non-micromanipulated, culture only. RESULTS: A total of 1222 embryos were divided among the four groups. In the study group 472 embryos underwent pronuclear microinjection and trophectoderm biopsy. Of these, 203 (43%) reached the blastocyst stage and underwent biopsy; 183 (38.8%) re-expanded after biopsy. Of 275 pronuclear microinjected only (control 1) embryos, 113 (41.1%) reached the blastocyst stage. Of 336 embryos 148 (44.0%) reached the blastocyst stage and underwent trophectoderm biopsy only (control 2); 129 (39.2%) survived biopsy. The cultured only group (control 3) consisted of 139 pronuclear embryos; 67 (48.2%) developed to the blastocyst stage. CONCLUSIONS: Murine embryos can survive two micro-manipulations, pronuclear microinjection followed by trophectoderm micro-biopsy. Although there is minimal effect of these procedures on embryonic development in vitro, the live birth rate is tenuous.

Animals↗
PubMed1994

Intrauterine insemination in fertile women delivers larger number of sperm to the peritoneal fluid than intracervical insemination.

Randomized IUI or intracervical insemination of eight fertile women with 50 x 10(6) sperm was performed to determine whether IUI delivers more spermatozoa to the peritoneal cavity. After IUI (n = 4), 2,053 to 29,450 sperm were recovered in the PF at laparoscopy. No sperm were found in the PF after intracervical insemination (n = 4). After IUI, CM contained 1.0 x 10(6) to 57.0 x 10(6) sperm/mL; after intracervical insemination, 0 to 1.2 x 10(3) sperm/mL were seen. One therapeutic mechanism for IUI is delivery of larger sperm numbers to the fertilization site by rapid (4 hours) transport. In addition, there is greater retrograde colonization of CM that may result in sustained release of sperm.

Cervix Uteri↗
PubMed1993

Embryonic platelet activating factor production in the rabbit increases during the preimplantation phase.

OBJECTIVE: This study measured platelet activating factor (PAF) production by rabbit embryos in vitro and ascertained if there is increased PAF production associated with advancing embryonic development. STUDY DESIGN: Two-cell rabbit embryos were recovered from superovulated New Zealand White does and cultured in vitro for 96 hr. Every 24 hr embryos were scored for developmental stage and PAF activity from the corresponding culture medium was measured by platelet aggregation and organic phosphate analyses. RESULTS: PAF was detected in culture medium at all stages from two cells to blastocysts and rose significantly (P < 0.001) at each 24-hr interval, reaching maximal levels at the expanded blastocyst stage. CONCLUSION: Maximal PAF production by expanded blastocysts may be an embryonic paracrine signal that facilitates implantation.

Animals↗
PubMed1993

Trophectoderm microbiopsy in murine blastocysts: comparison of four methods.

PURPOSE: This study compares four trophectoderm microbiopsy techniques for removal of blastomeres from murine blastocysts: (1) aspiration, trophectoderm pipetted through the zona; (2) incision, trophectoderm excised with a microrazor; (3) slit/excision, the zona slit and herniating trophectoderm excised; and (4) hatch/excision, trophectoderm cells excised after spontaneous hatching. RESULTS: Murine blastocysts were comparatively biopsied using one of four methods and contrasted to zona slit and nonmicromanipulated controls. Operative cellular injury was assessed by uptake of fluorescein isothiocyanate (FITC). Postoperative embryonic viability was assessed by blastocoele reexpansion and hatching inner cell mass development and trophectoderm plating. All techniques yielded cells available for genetic analysis. CONCLUSIONS: The slit/excision technique and hatch/excision techniques exhibited lower operative injury and the higher postoperative viability than aspiration or incision. The slit/excision and the hatch/excision techniques, though requiring two operative steps, appear to be the least damaging of the four methods. Therefore, they should be most applicable to human blastocysts obtained either by extended culture in vitro or by uterine lavage.

Animals↗
PubMed1993

Oral dehydroepiandrosterone in physiologic doses modulates immune function in postmenopausal women.

OBJECTIVE: This study tests the hypothesis that dehydroepiandrosterone or its metabolic products are immunomodulatory in postmenopausal women with relative adrenal androgen deficiency. STUDY DESIGN: A prospective, randomized, double-blind, crossover study of 11 subjects with 3-week treatment arms separated by a 2-week washout period was performed. Immunologic evaluation at the beginning and end of the treatment arms consisted of flow cytometry to delineate T-cell populations, in vitro T-cell mitogenic response and cytokine production, and natural killer cell cytotoxicity. Statistical analysis was based on a split-plot design with analysis of variance with repeated measures. RESULTS: Dehydroepiandrosterone supplementation decreased CD4+ (helper) T cells and increased CD8+/CD56+ (natural killer) cells. Although T-cell mitogenic and interleukin-6 responses were inhibited, natural killer cell cytotoxicity increased dramatically. CONCLUSIONS: These data provide the first in vivo evidence in human for an immunomodulatory effect of dehydroepiandrosterone. The salutary immune changes could account for clinical and experimental evidence of antioncogenic effects of this steroid. This study provides a strong rationale for further clinical studies on dehydroepiandrosterone supplementation in adrenal androgen-deficient states.

Aged↗
PubMed1993

Predicting pregnancy survival from a single first trimester vaginal ultrasonogram.

This retrospective study evaluates early first trimester FHR, gestational SACD, and CRL measurements as means to predict ultimate pregnancy outcome. Outcomes of 274 pregnancies were monitored a single time by transvaginal ultrasonography with measurements recorded between 5.0 and 9.0 weeks' gestation. The measurements were then correlated with the pregnancy outcomes. FHR (P < 0.0001), gestational SACD (P = 0.0002), and CRL (P = 0.0059) each correlated positively with a successful pregnancy outcome. Measurements from a single transvaginal ultrasonogram can be used to predict a successful pregnancy outcome in the early first trimester.

Anthropometry↗
PubMed1992

Mechanisms of insulin inhibition of ACTH-stimulated steroid secretion by cultured bovine adrenocortical cells.

Results of previous studies indicated that insulin at levels comparable to those in humans during hyperinsulinemia decreased ACTH-stimulated cortisol and androstenedione secretion by bovine adrenal fasciculata-reticularis cells in primary culture. In the present studies this inhibitory action was examined further by comparing the effects of insulin on ACTH-stimulated corticosteroid secretion with its effects on 8-(4-chlorophenylthio)-cAMP (cpt-cAMP), forskolin- and [5val]angiotensin II (Ang II)-stimulated corticosteroid secretion. Effects on corticosteroid secretion were correlated with effects on cAMP accumulation and rates of cAMP production. Monolayers were incubated for 24 h in the absence or presence of each agonist alone or in combination with insulin. Insulin (1.7 x 10(-9) or 17.5 x 10(-9) M) caused about a 50% decrease in cortisol and androstenedione secretion in response to ACTH (10(-11) or 10(-8) M). Insulin also decreased ACTH-stimulated aldosterone secretion by cultured glomerulosa cells. Cpt-cAMP (10(-4) or 10(-3) M)-stimulated increases in cortisol and androstenedione secretion were inhibited by insulin, but to a lesser extent than those in response to ACTH. The inhibition of cpt-cAMP-stimulated steroid secretion was not related to increased degradation of the cyclic nucleotide. Increases in cortisol and androstenedione secretion caused by a submaximal concentration (10(-6) M) of forskolin were decreased 50-70% by insulin. In contrast, insulin failed to significantly affect cortisol or androstenedione secretion caused by a maximal concentration (10(-5) M) of forskolin. The secretory responses to Ang II (10(-8) M) were also unaffected by insulin. The effect of insulin to inhibit ACTH-stimulated steroid secretion was accompanied by a reduction in cAMP accumulation as well as an apparent inhibition of adenylate cyclase activation. These data indicate that the effect of insulin to attenuate ACTH-stimulated corticosteroid secretion results from both an inhibition of ACTH-stimulated adenylate cyclase activity and an antagonism of the intracellular actions of cAMP.

1-Methyl-3-isobutylxanthine↗
PubMed1992

Serum progesterone and uterine curettage in differential diagnosis of ectopic pregnancy.

The implementation of a serum P less than 5.0 ng/mL is important because it resolves the differential diagnosis of EP by enabling timely uterine curettage. Curettage with examination of curettings or documentation of falling hCG can be used to prevent unnecessary laparoscopies in patients undergoing spontaneous abortions and can make possible definitive diagnosis and medical treatment of EP completely eschewing anesthesia and surgery.

Curettage↗