PubMed Health⌕ Search

Biomedical subjects

R K Iles

Publications and source records attributed to R K Iles.

At least 55 records · Page 3Linked to original sources
PubMed1994

Serum placental-type alkaline phosphatase activity in women with squamous and glandular malignancies of the reproductive tract.

AIM: To investigate serum placental-type alkaline phosphatase (PLAP-type) activities in women with squamous and glandular malignancies of the reproductive tract using an immunoradiometric assay. METHODS: PLAP-type immunoreactivity was measured in 180 women with non-ovarian malignancies of the reproductive tract and the values were compared with those from 334 controls. The cases comprised 18 vulval, nine vaginal, 103 cervical, 46 endometrial, and five fallopian tube cancers. RESULTS: Serum PLAP-type activities were no different from controls in patients with squamous cell tumours. Women with adenocarcinoma of the cervix, endometrium, and fallopian tube had increased values: women with endometrial cancer had a median value nearly four times greater than that of controls. There was no direct correlation between PLAP-type activities and stage of disease in patients with endometrial cancer, but values reverted to normal after treatment. CONCLUSIONS: Serum PLAP-type measurements are of no value in the management of patients with squamous cell tumours of the female reproductive tract. Raised activities can, however, be found in glandular tumours, in particular endometrial cancer where serum PLAP-type measurements may be of value in predicting remission.

Adenocarcinoma↗
PubMed1993

Urinary chorionic gonadotropin subunits and beta-core in nonpregnant women. A study of benign and malignant gynecologic disorders.

BACKGROUND: The presence of urinary excretion products of human chorionic gonadotropin (hCG) has been proposed as a tumor marker. To ascertain the clinical value in gynecologic cancers, the authors studied 612 nonpregnant women. METHODS: Three different assays in four clinical groups were compared: no disease, benign disease, malignant disease, and complete remission of previously treated malignant disease. The assays were for the urinary beta-core, "total" beta-hCG, and free alpha-subunit. RESULTS: Measurement of the alpha-subunit was of no obvious clinical value. In some patients with benign disease, hCG metabolites were elevated. In the 141 patients with active gynecologic malignancy the sensitivity of the total beta-hCG assay was 47% and that of the beta-core assay was 36%. The specificities were 80.3% and 90.4%, respectively. Advanced cancers generally had higher levels of total beta-hCG and beta-core. Squamous cell and poorly differentiated cervical tumors had higher levels of total beta-hCG than did adenocarcinomas and well-differentiated cervical tumors. Invasive, serous, endometrioid, and germ cell ovarian tumors had higher total beta-hCG, beta-core, and alpha-subunit levels than did borderline, mucinous, and clear cell ovarian tumors. Six of 16 patients with disease in complete remission had elevated levels. CONCLUSION: The excretion of hCG and its metabolic fragments is a common event in gynecologic cancer, but sensitivity and specificity are low, and there is little consistent relationship between tumor stage and histologic type.

Adenocarcinoma↗
PubMed1993

Serum PAPP-A measurements in first-trimester screening for Down syndrome.

Serum PAPP-A measurements taken from 254 women in the first trimester are reported. Eleven chromosomal abnormalities were detected. The mean serum PAPP-A levels in cases of Down syndrome were 0.44 MOM at 9 weeks gestation, 0.15 MOM at 10 weeks, and 0.29 MOM at 11 weeks. The PAPP-A level at 10 weeks was below those of pregnancies which aborted spontaneously. At 11 weeks, the pregnancies with Down syndrome recorded the lowest PAPP-A levels at that gestation. On this small sample, offering chorionic villus sampling to women with singleton pregnancies and a PAPP-A level below 0.3 MOM (approximately 6.5 per cent of this at-risk group) would have detected all the Down syndrome fetuses at 10 weeks and 50 per cent at 11 weeks without selecting those cases destined to abort. This suggests that serum PAPP-A should continue to be investigated as a potential first-trimester screening test for Down syndrome.

Adult↗
PubMed1993

The measurement of urinary beta core fragment in conjunction with serum CA125 does not aid the differentiation of malignant from benign pelvic masses.

The urinary concentration of the renal metabolite of the beta subunit of human chorionic gonadotropin (beta core) has been proposed as a tumor marker in certain nontrophoblastic malignancies including those of the female genital tract. A previous study investigated the use of urinary beta core in conjunction with serum CA125 in distinguishing malignant from benign pelvic masses and showed that the combined test improved the overall sensitivity to 88%; this was greater than that for either test alone. However, the cutoff levels used to distinguish normal from abnormal were approximately six times greater than those generally used for CA125 and four to five times lower than those used for beta core in our laboratory. Furthermore there was no recognition of the possible difference in normal levels of beta core between pre- and postmenopausal women. We have examined a similar group of cases using our cutoff levels for urinary beta core of 0.36 ng/ml in premenopausal women and 0.48 ng/ml in postmenopausal women and 35 u/ml for CA125. We show that measurement of CA125 is substantially more sensitive that that of beta core and that the combination of beta core with CA125 does not improve the overall sensitivity of the test. However, there was a small improvement in positive predictive value if both tests were positive (97.5%) and of specificity when one or the other test was negative (98.5%).

Adult↗
PubMed1993

Low levels of amniotic fluid placental alkaline phosphatase in Down's syndrome.

OBJECTIVE: To investigate amniotic fluid placental alkaline phosphatase (PLAP) levels in normal and trisomy 21 pregnancies. DESIGN: Cross sectional study. SETTING: A tertiary referral prenatal diagnostic service. SUBJECTS: Three hundred and eleven women with singleton pregnancies of normal karyotype between 10 and 23 weeks gestation and 31 women with pregnancies associated with trisomy 21 Down's syndrome. OUTCOME MEASURES: PLAP levels were measured by immunoradiometric assay in amniotic fluid obtained by amniocentesis. RESULTS: Amniotic fluid PLAP was detectable from 12 weeks gestation and the median value rose to a peak of 4.57 iu/l at 18 weeks. Pregnancies associated with Down's syndrome had significantly lower levels with a median multiple of median (MoM) of 0.638, (U = 3374, P = 0.0016, 95% CI = 0.50, 0.89). For the 20 women with trisomy 21 pregnancies detected at 16 to 18 weeks, the median MoM was 0.482, (U = 3694, P = 0.0011, 95% CI = 0.37, 0.85). CONCLUSION: These data demonstrates that PLAP levels are reduced in the amniotic fluid of women carrying a fetus with trisomy 21.

Alkaline Phosphatase↗
PubMed1993

Substantial urinary concentrations of material resembling beta-core fragment of chorionic gonadotropin beta-subunit in mid-menstrual cycle.

We measured the day-to-day variations in concentrations of beta-core, luteinizing hormone (LH), and alpha-subunit in urine during the menstrual cycle. The alpha-subunit concentrations showed a pattern similar to that of the LH concentrations. beta-Core-like material was increased during and up to 3 to 4 days after the surge in urine LH. The urine LH concentration was associated with the presence of beta-core immunoreactivity during the urine LH peak. Chromatography showed that, at the peak LH concentration and at 2 days after the LH peak, beta-core immunoreactivity could be accounted for by the presence of a peptide of low molecular mass similar to the beta-core molecule of hCG, but probably originating from the degradation of LH. The prolonged excretion of gonadotropin metabolites in the midcycle must be considered when beta-core is being assessed as a tumor marker.

Adult↗
PubMed1992

Immunoreactive beta-core-like material in normal postmenopausal urine: human chorionic gonadotrophin or LH origin? Evidence for the existence of LH core.

Material with the immunochemical properties of the beta-core of human chorionic gonadotrophin (hCG) can be found in the urine of normal postmenopausal women. However, we have been unable to detect intact hCG (using an assay which is specific for the alpha-beta heterodimer of intact hCG) in serum of such subjects. The levels of serum LH and urinary beta-core were compared in matched samples from 28 women (serum LH: median 27 U/l, range 4-70 U/l, urinary beta-core: median 0.27 microgram/l, range less than 0.05-0.645 microgram/l). Urine (4 litres) from three postmenopausal women was concentrated, dialysed and subjected to gel exclusion chromatography on Sephadex G-100. Fractions were analysed by specific assays for LH, intact hCG, total beta-hCG (free beta-subunit and intact hCG), free alpha-subunit and beta-core. Material eluting at the expected position of the beta-core fragment of hCG was detected in all three samples by the beta-core, beta-hCG and LH assays, despite the fact that the LH antibody does not recognize the authentic beta-core of pregnancy. Electrophoresis and Western blotting of the concentrated urines revealed that material of the same molecular size as beta-core was recognized by the antibody to LH but not by a monoclonal antibody raised to free beta-hCG which also recognizes the beta-core molecule of hCG. We conclude that the predominant core-like material identified in postmenopausal urine is probably derived from the beta-subunit of LH.

Aged↗
PubMed1992

Human chorionic gonadotrophin and subunit composition of maternal serum and coelomic and amniotic fluids in the first trimester of pregnancy.

Sixteen matched samples of first trimester amniotic fluid (AF), extraembryonic coelomic fluid (EECF) and maternal serum (MS) were assayed for intact human chorionic gonadotrophin (hCG) and free subunits. Total beta-hCG (free beta-subunit and intact hCG) levels in the EECF (median 410 kIU/l) were 61 times greater than levels in AF (median 6.73 kIU/l) and 2.8 times greater than in MS (median 141.5 kIU/l). Levels of intact hCG in the EECF (median 245 kIU/l) were 142 times greater than in AF (median 1.73 kIU/l) and 1.6 times greater than in MS (median 157 kIU/l). Free alpha-subunit levels in EECF (median 17.3 mg/l) were 66 times greater than in AF (median 0.262 mg/l) and 12 times greater than in MS (median 1.3 mg/l). Virtually all of the total beta-hCG immunoreactivity in MS can be attributed to intact hCG, but only 60% of total beta-hCG in the EECF and 20% of that in AF can be accounted for by the intact hormone. In both EECF and AF the free alpha-subunit was a major constituent; on a molar basis the ratio of free alpha:free beta:intact hCG was 1:1.2:0.3 in AF, 1:0.6:0.5 in EECF and 1:0:5 in MS. Chromatography of MS, EECF and AF on Sephadex G-100 confirmed the hCG and subunit composition of the fluids. On the basis of these findings it seems likely that previous studies showing very high levels of hCG in AF during the first trimester may have incorrectly sampled the EECF. In reality, the levels of total hCG (and free subunits) are low in the AF, and only 20% is intact hCG.(ABSTRACT TRUNCATED AT 250 WORDS)

Amniotic Fluid↗
PubMed1991

Purification and assay of insulin-like growth factor-binding protein-1: measurement of circulating levels throughout pregnancy.

Insulin-like growth factor-binding protein-1 (IGFBP-1) has been purified from amniotic fluid by anion exchange, hydrophobic interaction and gel filtration chromatography. The overall recovery of the purification process was 12.2%. The purified IGFBP-1 yielded a single band on SDS-PAGE gel but showed two bands (34 kDa and 68 kDa) on Western blot under non-reducing conditions. Polyclonal antisera were raised by immunization of sheep using the purified IGFBP-1. The best antiserum bound 50% of 125I-labelled IGFBP-1 at a final dilution of 1:500,000. A radioimmunoassay for IGFBP-1 was developed. This assay had a minimum detection limit of 5 micrograms/l, and was used to determine serum levels in non-pregnant and pregnant women. There was no cross-reaction with a wide variety of materials tested. Serum IGFBP-1 levels in non-pregnant individuals (33 +/- 16 (S.D.) micrograms/l) were found to be significantly lower than those in the second (96 +/- 64 micrograms/l) and third trimesters (95 +/- 60 micrograms/l) of pregnant women. During pregnancy, circulating IGFBP-1 levels increased rapidly in the first trimester and reached a peak at 12-13 weeks of gestation (107 +/- 75 micrograms/l). The level then remained at 80 +/- 53 to 103 +/- 70 micrograms/l until term.

Adolescent↗
PubMed1991

The purification and development of a radioimmunoassay for beta-core fragment of human chorionic gonadotrophin in urine: application as a marker of gynaecological cancer in premenopausal and postmenopausal women.

The beta-core fragment of human chorionic gonadotrophin (hCG) is a major part of the immunoreactive hCG-like material found in the urine of normal pregnant women. Patients with non-trophoblastic gynaecological malignancies have been found to have raised levels of urinary beta-core. We describe the purification of beta-core, the preparation of a polyclonal sheep antiserum and the development of radioimmunoassay. The minimum detection limit of this assay was 0.025 micrograms beta-core/l. There was no significant cross-reaction with the free alpha-subunit, hLH, hFSH and hTSH (less than 0.7%), and only partial cross-reaction with intact hCG and free beta-subunit of hCG (6.9 and 18%). Within-assay variability ranged from 2.03 to 12.5% and between-assay variability from 2.25 to 13.4%. The assay was applied to urine samples from 92 normal non-pregnant premenopausal women, 54 normal postmenopausal women and 65 women with active gynaecological disease (47 postmenopausal and 18 premenopausal). In normal premenopausal women the values ranged from less than 0.025 to 0.62 micrograms beta-core/l (median 0.043 micrograms beta-core/l). The values for normal postmenopausal women ranged from less than 0.025 to 0.64 micrograms beta-core/l (median 0.26 micrograms beta-core/l). Postmenopausal women with gynaecological malignancy had values which ranged from less than 0.025 to 4.0 micrograms/beta-core/l (median 0.31 micrograms beta-core/l); premenopausal women in this group had values which ranged from less than 0.025 to 1.15 micrograms beta-core/l (median 0.12 micrograms beta-core/l). On molecular sieve chromatography, the material found in the urine of normal postmenopausal women showed the physicochemical characteristics of authentic beta-core.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Expression of beta human chorionic gonadotrophin by non-trophoblastic non-endocrine 'normal' and malignant epithelial cells.

Expression of hCG and its free subunits by non-trophoblastic tumours is well recognised. Previously we reported hCG secretion by normal and malignant bladder epithelial cells in vitro. Here we examined culture medium from 83 different cell lines derived mainly from common epithelial tumours. Thirty-two of the cell lines were found to secrete hCG-like material into their culture media. Partial immunochemical characterisation showed that of these only choriocarcinoma and fetal tissue cell lines produced intact hCG and alpha subunit. The remaining 28 hCG-expressing epithelial cell lines, which are of mucosal origin, only secreted free beta subunit. Expression of free beta hCG by non-trophoblastic nonendocrine cells would appear to be especially characteristic of mucosal epithelia from the genitourinary and oral/respiratory tracts. Furthermore, this phenomenon may be characteristic of epithelium with transitional and/or squamous cell-like properties.

Carcinoma↗
PubMed1990

Composition of intact hormone and free subunits in the human chorionic gonadotrophin-like material found in serum and urine of patients with carcinoma of the bladder.

Ectopic-hCG production occurs in approximately 30% of urothelial cancers. However, the clinical features which might be expected to result from elevated hCG levels are rare. We now show that in six of seven metastatic and 20 of 21 localized (Ta-T4) positive hCG bladder cancer patients, only the free beta-subunit of hCG and its respective urinary breakdown product, beta-core, could be detected in clinical samples. Since only intact hCG is biologically active, this explains the discrepancy between biochemical and clinical findings.

Aged↗