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Biomedical subjects

J A Holt

Publications and source records attributed to J A Holt.

At least 19 recordsLinked to original sources
PubMed1992

Correlation of cervicovaginal fluid volume with serum estradiol levels and total follicular volume during human gonadotropin stimulation.

During the normal menstrual cycle the volume of cervicovaginal fluid (CVF), as determined by the patient at home using a simple volumetric aspirating pipette, increases significantly over several days prior to the luteinizing hormone (LH) surge and decreases characteristically shortly after ovulation. The present study was undertaken to test the hypothesis that self-determined measurements of CVF volume would correlate positively with serum estradiol (E2) levels and with total follicular volume (TFV) in cycles stimulated with exogenous gonadotropins. Consequently, 20 infertility patients, undergoing human menopausal gonadotropin (hMG)-stimulated cycles, were asked to measure daily CVF. Routine serum E2 determinations and vaginal follicular ultrasound studies were performed up to and including the day of human chorionic gonadotropin (hCG) administration (designated day 0). The mean daily CVF volume (+/- SD) increased from 0.1 +/- 0.01 ml on day -6 to 0.7 +/- 0.40 ml on day -1 and then decreased to 0.6 +/- 0.40 ml on day 0. On day 0, 7 of 20 cycles (35%) demonstrated a decrease in CVF, which ranged from 0.1 to 1.0 ml (mean, 0.42 ml). The mean daily CVF correlated positively (correlation coefficient = r) with the mean daily serum E2 (r = 0.89) and with the mean daily TFV (r = 0.88). The mean daily correlation of TFV for E2 was r = 0.98. The correlation between CVF and E2 of individuals ranged from r = 0.38 to r = 0.99 and the correlation between CVF and TFV ranged from r = 0.12 to r = 1.0, while the individual correlations of E2 to TFV ranged from r = 0.60 to r = 0.99.(ABSTRACT TRUNCATED AT 250 WORDS)

Cervix Mucus↗
PubMed1992

Detection of the HER-2/neu proto-oncogene protein p185erbB2 by a novel monoclonal antibody (MAB-145ww) in breast cancer membranes from oestrogen and progesterone receptor assays.

Amplification of the proto-oncogene HER-2/neu and/or overexpression of the transmembrane protein p185erbB2 that it encodes occur in approximately 30% of human breast and gynaecological cancers seen clinically and are strongly associated with an unfavourable outcome. We report on the use of a new monoclonal antibody (Mab-145ww) together with immunoblotting for detection of p185erbB2 in membranes that remain after routine processing of breast cancer tissue for steroid receptor assays. Human breast cancer cell lines SKBR3 and MCF-7 were used as high and low controls, respectively, for p185erbB2 expression. Mab-145ww was detected p185erbB2 in more than half of the breast cancer specimens; the expression was intense in SKBR3 cells, but only faint in MCF-7 cells. These results demonstrate that routine processing of cancer tissue for steroid receptor status can include providing a preparation with which to assess p185erbB2 expression and, thus, can provide information potentially useful for the clinical management of individual cancer patients.

Antibodies, Monoclonal↗
PubMed1992

Intracellular actions of steroid hormones and their therapeutic value, including the potential of radiohalosteroids against ovarian cancer.

The biological activities of steroid hormones are effected via intracellular receptors. The receptors are part of a ligand-activated family of transcription regulator proteins that are critical for steroid-regulated cell differentiation. With recombinant cDNA technology, yeast and cultured animal cells can be made to express mammalian cDNA steroid receptors from cDNA clones that contain deletions and substitutions. Among the leading problems addressed in these models is the characterization of sequences that promote association or interaction with other transcription regulating molecules, including oncogene products. Recently it has been found that heat shock proteins may serve not only to stabilize the receptor proteins but also to precondition the activation imparted by ligand binding. Aberrant receptor proteins can be found in ovarian cancer. Whether aberrant receptor proteins are associated with transformation in general or with a variable clinical response to steroidal or anti-steroidal therapy is not known. Even after chemotherapy, steroid receptors are expressed in the metastases of ovarian cancers seen clinically, and they may have potential uses for localization and treatment of receptor-rich cancers. Radioligand pharmaceuticals appropriate for imaging or for site-directed radiocytotoxicity can be sequestered to the nuclei of receptor-rich cancers. Initial clinical imaging and therapy trials with such pharmaceuticals have been approved and begun. In the use of halogenated estrogen radiopharmaceuticals, liver metabolism and enterohepatic recirculation are important considerations. Ascites prolongs retention of a radiohalogenated estrogen in the abdominal cavity. Distant metastases have been localized with [123I]-estrogen in breast cancer patients in pre-operative procedures. Receptor-mediated cytotoxicity occurs when estrogen receptor radioligand pharmaceuticals that are Auger electron emitters are used in vitro.

Animals↗
PubMed1992

[Regulation of sterol carrier protein-2 in human luteal cells by LH and LH-RH].

Conversion of cholesterol to pregnenolone is the most important and, at the same time, the rate-limiting step of steroidogenesis. Sterol carrier protein-2 (SCP2) or nonspecific lipid transfer protein (nsL-TP) is an intracellular protein, which plays an important role in the pre- and transmitochondrial transport of cholesterol and for the mitochondrial synthesis of pregnenolone. Synthesis of pregnenolone in rat Leydig cells can be increased by LH and LH-RH; however, only LH leads to characteristic changes in intracellular concentrations of SCP2. This means that synthesis of pregnenolone is regulated in two different ways. In this study we aimed to find out whether such a 'second way' of steroidogenesis is also demonstrable for the human corpus luteum (i.e. human luteal cells). Human luteal cells were collected during follicle punctures and were cultured as described previously. We demonstrate that (human) LH/hCG are able to enhance pregnenolone synthesis; this process is accompagnied by typical changes of SCP2 and an increase in activity of 7-dehydrocholesterol reductase, which is a marker enzyme for SCP2. LH-RH was shown to exert no effect. Thus, we conclude that a second way of steroidogenesis (i.e. synthesis of pregnenolone) cannot be proved for the human corpus luteum.

Carrier Proteins↗
PubMed1991

Prolonged clearance of intraperitoneal 16 alpha-[125I]iodo-17 beta-estradiol in presence of ascites.

Radioestrogens have potential as adjunct therapeutic agents against ovarian carcinoma, because selected radionuclides can deposit lethal doses of radiation to tumor cells and many ovarian carcinomas and their metastases express estrogen receptors. Because intraperitoneal administration is a possible approach, we investigated absorption from the peritoneal cavity of a radioiodoestradiol after intraperitoneal application in rats with and without ovarian tumors and ascites and compared the distribution of the radioactivity with that obtained after intravenous injection. In the absence of ascites, 70% of the intraperitoneal dose was cleared into the intestine within 2 hours after injection, indicating fast absorption from the peritoneal cavity. In the presence of ascites, clearance of intraperitoneal radioiodoestradiol was considerably slower; at 2 hours after injection, 50% of the injected dose remained in the ascites, mostly as radioiodoestradiol. Uptake of radioactivity in estrogen receptor-rich tissues, e.g., uterus, after intraperitoneal injection was high (about 20:1 over blood), regardless of the presence of ascites, but moderately lower than that observed after intravenous injection of radioiodoestradiol.

Animals↗
PubMed1991

Biodistribution, with high uptake by the reproductive tract, of an intraperitoneally infused radiohalogenated steroidal estrogen-receptor ligand.

We infused [123I]16 alpha-(123I)-iodo-estradiol ([123I]E2) intraperitoneally (i.p.) into swine to study its biodistribution and to explore the i.p. use of radiohalogenated steroid estrogen-receptor (ER) ligands as a potential option for diagnosing and treating intra-abdominal, retroperitoneal, and distant sites of advanced ER-rich malignancies. Fifty to 80% of the radiolabel was absorbed from the peritoneal cavity within 30 minutes, and 30 to 50% of the infused radiolabel was excreted in the urine within 2 hr. The rate of biliary clearance was maximal within 25 minutes. At 3 hr, the ER-rich reproductive tract had greater than 63 times the concentration of radiolabel in blood; the former was blocked by non-labeled competitors for ER. Uptake by non-ER-rich tissues, compared to blood, ranged from 0.7:1 (heart and lungs) to 16:1 (spleen); the omentum, however, exhibited a concentration as high as 64:1, which was not blocked by non-labeled ER ligands. Uptake by ER-rich target tissue remained high when charcoal was used to prevent reabsorption of radiolabel from the digestive tract after its biliary excretion, and when the products of biliary excretion were removed by catheterization of the common bile duct. Neither charcoal nor exteriorization of bile appeared to affect urinary clearance of the radiolabel over the time course of the experiments. Taken together with the recent development of syntheses that yield radiohalogenated sex steroid receptor ligands of high specific activity, our findings are encouraging for the potential application of radiolabeled ligands as i.p. administered pharmaceuticals. The advantage of the i.p. route is that it provides direct uptake of the pharmaceutical by free-floating clusters and individual cancer cells in ascitic fluid, as well as delivery via the circulation to vascularized intra- and/or extraperitoneal metastases.

Abdomen↗
PubMed1991

Rapid liver metabolism, urinary and biliary excretion, and enterohepatic circulation of 16 alpha-radioiodo-17 beta-estradiol.

The radiohalogenated estrogen 16 alpha-[123I]iodo-17 beta-estradiol ([123I]E2) is emerging as a diagnostic tool for imaging of ER-rich malignant tumors, with potential application for site-directed radiotherapy. Clinical use requires an accurate accounting for the biodistribution of the radioactivity, including an assessment of its enterohepatic circulation. We investigated the metabolism and circulation of [125I]E2 in the enterohepatic system in swine, a pharmacokinetic model that resembles humans. With indicator dilution methods, we found that, after its injection into the portal vein, more than 99% of [125I]E2 was cleared from the blood by the liver during the first pass. Water-soluble metabolites were then partly released into the blood and partly excreted into bile. After injection of [125I]E2 into the external jugular vein, one-third of the radioactivity was excreted in bile and two-thirds in the urine. More than 90% of the radioactivity in urine and bile was that of [125I]E2-glucuronide or [125I]E2-sulfate; only a very small fraction of the excreted radioactivity was from free 125I. Radioactivity in bile collected from one swine after i.v. injection of [125I]E2, and then infused into the proximal duodenum of a second swine, was almost totally absorbed during passage through the intestine at 5-7 hr after infusion. The reabsorbed radioactivity was cleared in the urine.

Animals↗
PubMed1991

Antigen CA 19-9: presence in mucosa of nondiseased müllerian duct derivatives and marker for differentiation in their carcinomas.

CA 19-9, a side branch of the Lewis blood group system, is a sialylated Lewis A antigen that is highly expressed by many adenocarcinomas of the digestive tract. The müllerian duct-derived mucosa of the uterus and fallopian tubes also synthesizes Lewis blood group antigens. To test whether the expression of CA 19-9 is enhanced in carcinomas of müllerian duct origin, we performed immunohistochemical staining for CA 19-9 in normal tissues from 33 women and in adenocarcinomas from 88 patients. In the normal uterine cervix, CA 19-9 was expressed in the cytoplasm of scattered glandular cells in 26 of 29 specimens. It was observed in the apical regions of mucosal cells in six of 26 normal endometrial samples and two of 13 normal fallopian tube specimens. These results are consistent with the presence of antigen CA 19-9 on a secretory product of the nondiseased mucosa of the müllerian duct. In adenocarcinomas of the endocervix, endometrium, and fallopian tubes, CA 19-9 was found in seven of 11, 57 of 71, and five of six samples, respectively. Progressive loss of differentiation was accompanied by disruption of subcellular localization of CA 19-9 and its secretion toward the glandular lumina. In well-differentiated regions of tumors, the antigen was detected mainly at the luminal surface of cancerous glands, whereas the staining was mostly cytoplasmic or vacuolar in less differentiated areas. The degree of CA 19-9 expression was inversely related to tumor differentiation (P less than .001).

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1990

Quantitative and qualitative tests for urinary luteinizing hormone. Comparison in spontaneous and clomiphene-citrate-treated cycles.

A study was performed to evaluate conditions in which false-positive and -negative predictions of ovulation occur with qualitative urinary luteinizing hormone (LH) tests. Three urine specimens and a serum sample were collected daily for LH determination from five anovulatory women treated with clomiphene citrate and from six spontaneously cycling women. The urinary LH was determined with one quantitative and three qualitative tests, and the serum LH was determined with a quantitative assay. Ovulation was determined with transvaginal ultrasound and a serum progesterone level on day 22 of the menstrual cycle. There were six ovulatory and five anovulatory cycles. In those 11 cycles the qualitative urinary LH tests were falsely positive twice and falsely negative thrice. All the false-positive and -negative tests except for one occurred when the quantitative urinary LH was 24-28 mIU/mL. Two false-positive tests occurred one to two days after clomiphene administration. Two false-negative tests occurred in a cycle in which follicular development appeared suboptimal, and one occurred in a cycle with a brief urinary LH surge.

Clomiphene↗
PubMed1989

Studies of the HER-2/neu proto-oncogene in human breast and ovarian cancer.

Carcinoma of the breast and ovary account for one-third of all cancers occurring in women and together are responsible for approximately one-quarter of cancer-related deaths in females. The HER-2/neu proto-oncogene is amplified in 25 to 30 percent of human primary breast cancers and this alteration is associated with disease behavior. In this report, several similarities were found in the biology of HER-2/neu in breast and ovarian cancer, including a similar incidence of amplification, a direct correlation between amplification and over-expression, evidence of tumors in which overexpression occurs without amplification, and the association between gene alteration and clinical outcome. A comprehensive study of the gene and its products (RNA and protein) was simultaneously performed on a large number of both tumor types. This analysis identified several potential shortcomings of the various methods used to evaluate HER-2/neu in these diseases (Southern, Northern, and Western blots, and immunohistochemistry) and provided information regarding considerations that should be addressed when studying a gene or gene product in human tissue. The data presented further support the concept that the HER-2/neu gene may be involved in the pathogenesis of some human cancers.

Animals↗
PubMed1989

Binding of radiolabeled estrogens by human cells in vitro: implications to the development of a new diagnostic and therapeutic modality in the treatment of malignancies with estrogen receptors.

An in vitro technique was employed to demonstrate the binding of Auger electron-emitting nuclide-labeled estrogenic compounds by a variety of human cell types. Human granulosa cells, endometrium, and MCF-7 breast cancer cells were incubated with either 16 alpha-[I125]-iodoestradiol-17 beta or 16 alpha-[I123]-iodoestradiol-17 beta in vitro. Autoradiographic techniques were subsequently utilized and revealed that binding of these estrogenic compounds by all three types of cells did occur and that this binding was inhibited by excess unlabeled estradiol. Histologic examination was not able to demonstrate nuclear-specific binding in all instances, however. These compounds are potentially useful in both diagnostic and therapeutic settings and this study is the first to provide such data from human tissue.

Autoradiography↗
PubMed1989

Regulation of progesterone production in the rabbit corpus luteum.

Substantial evidence accumulated over six decades has established that estradiol exerts a dominant stimulatory influence on the production of progesterone by luteal tissue in pseudopregnant or pregnant rabbits, beginning approximately five days after ovulation. The direct steroidogenic action of estradiol on the luteal cell is mediated by the estrogen-receptor protein complex at the nuclear level. Major effects of estradiol lie distal to cholesterol ester and the formation of lipid droplets, and proximal to cholesterol availability for translocation into cytochrome P-450 cholesterol side-chain cleavage enzyme (P-450scc). Structure-function studies corroborate this as an estrogen-sensitive segment of the steroidogenic pathway in the rabbit corpus luteum. Estradiol increases the amount of precursor available for pregnenolone production in rabbit luteal mitochondria. Whether this is because of enhanced precursor storage in the mitochondria or because of effects on intramitochondrial movement of precursor, or both, is unclear. There is a void in knowledge between events at the nuclear level in response to the estrogen stimulus and known post-translational effects at the level of cellular and subcellular organelles. Studies to determine estrogen-sensitive transcriptional and translational events associated with steroidogenesis in the rabbit luteal cell model offer a novel perspective for an improved understanding of the regulatory processes governing steroidogenesis.

Animals↗
PubMed1989

IgG and IgA content of vaginal fluid during the menstrual cycle.

Immunoglobulin levels in cervicovaginal secretions during the menstrual cycle have not been well characterized biochemically. We determined the IgG and IgA concentrations in vaginal fluid obtained by patient self-sampling with an Ovu-Trac aspirator. Vaginal fluid IgG levels were less than 1-270 mg/dL. On the average the levels of IgG were relatively high after menstruation, declined during the ovulatory phase and remained relatively low during most of the luteal phase. The IgA levels were less than 10 mg/dL, and many samples contained IgA at our assay's lower limits of detection (microradial immunodiffusion). The preovulatory and luteal phase levels of IgG and IgA in vaginal fluid were generally lower than those reported for cervical mucus, but the ovulatory phase IgG and IgA composition was comparable between vaginal fluid and cervical mucus.

Body Fluids↗
PubMed1989

Multicenter evaluation of TDx test for assessing fetal lung maturity.

"TDx Fetal Lung Maturity," an automated assay that measures the relative concentrations of surfactant and albumin in amniotic fluid, was compared with the lecithin/sphingomyelin (L/S) ratio and phosphatidylglycerol determination at five clinical sites. A total of 695 amniotic fluid samples were analyzed, of which 312 were followed by delivery of the infant within three days of sample collection. Of these 312, 24 developed respiratory distress syndrome and seven developed transient tachypnea. With the cutoff for maturity set at a surfactant/albumin value of 50 mg/g, the assay showed a sensitivity of 0.96 and a specificity of 0.88 for all samples, compared with a sensitivity of 0.96 and a specificity of 0.83 for the L/S ratio. The combination of rapid assay (30 min), accurate results, and uniformity among testing centers makes the TDx assay a very promising method.

Albumins↗
PubMed1989

Assessment of hormone receptors in breast carcinoma by immunocytochemistry and image analysis. I. Progesterone receptors.

Frozen sections of 30 breast carcinomas were stained for progesterone receptors (PRs) using a rat monoclonal primary antibody and an alkaline phosphatase-antialkaline phosphatase technique. The micro-TICAS image analysis system was used for evaluation of the staining, with the results obtained by image analysis compared with the results of biochemical assays for PR. Strong positive/negative concordance (90%) was observed between the immunohistochemical and biochemical assays. However, the numerical values of the positive cases in the two assays did not correlate well, possibly because the biochemical assay does not take tumor cellularity into account. Three PR distribution patterns, designated A, B and C, were identified by image analysis among the breast tumors. In the type A pattern, tumor cell nuclei were diffusely and uniformly labeled. In type B, both clearly negative as well as distinctly positive cells were present. In type C tumors, a broad range of labeling reactions (from negative to intensely positive) was observed. These results imply (1) that the PR content of human breast carcinoma may be accurately and objectively assessed by the image analysis of immunohistochemically stained frozen sections, (2) that image analysis may provide a more accurate estimate of the cellular content of PR than do biochemical assays and (3) that PR distribution patterns obtained through image analysis permit the consistent appraisal of intratumoral heterogeneity of PR expression, which is potentially of prognostic importance.

Breast Neoplasms↗