Biomedical subjects

K Nustad

Publications and source records attributed to K Nustad.

At least 19 recordsLinked to original sources

PubMed2004

BRCA1 mutations in ovarian cancer and borderline tumours in Norway: a nested case-control study.

The aims of the present study were to find the frequency of the most common BRCA1 mutations in women with ovarian tumours identified from a population-based cancer registry and in the general population, to estimate the relative risk of ovarian tumours among the mutation carriers, and to explore the value of using CA125 as a prediagnostic test. The study was designed as a nested case-control study within a cohort mainly consisting of participants in population-based health examinations. The data files of The Cancer Registry of Norway and the Janus serum bank were linked to identify cases with ovarian cancer and borderline tumours. Hereditary BRCA1 mutations were determined using archived serum samples and capillary electrophoresis. Altogether 478 ovarian cancer patients and 190 patients with borderline tumours were identified, and 1421 and 568 matching controls were selected. Odds ratios (OR) of developing ovarian cancer and borderline tumours in the presence of BRCA1 mutations and CA125 level were derived from conditional logistic regression models. Among the 478 ovarian cancer patients, 19 BRCA1 mutations were identified (1675delA, 1135insA, 816delGT and 3347delAG), none among the patients with borderline tumours. Only two of the 1989 controls were BRCA1 mutation carriers (0.10%). The risk of ovarian cancer among the mutation carriers was strongly elevated (OR=29, 95% CI=6.6-120). CA125 was a marker for ovarian cancer, but the sensitivity was low. This study showed that BRCA1 mutation carriers have a very high risk of ovarian cancer. However, since the prevalence of BRCA1 mutations in the Norwegian population was low, the proportion of ovarian cancers due to BRCA1 mutations seemed to be low, about 4%. The sensitivity of using CA125 only as a screening test for ovarian cancer was low.

Adult↗

PubMed2001

Immunomagnetic DNA aptamer assay.

DNA aptamers, oligonucleotides with antibody-like binding properties, are easy to manufacture and modify. As a class of molecules, they represent the biggest revolution to immunodiagnostics since the discovery of monoclonal antibodies. To demonstrate that DNA aptamers are versatile reagents for use as in vitro diagnostic tools, we developed a hybrid immunobead assay based on a 5'-biotinylated DNA thrombin aptamer (5'-GGTTGGTGTGGTTGG-3') and an anti-thrombin antibody (EST-7). Our results show that the thrombin DNA aptamer is capable of binding to its target molecule under stringent in vitro assay conditions and at physiological concentrations. These findings also support the view that DNA aptamers have potential value as complementary reagents in diagnostic assays.

Antibodies, Monoclonal↗

PubMed2000

Predictive values of serum tumour markers tetranectin, OVX1, CASA and CA125 in patients with a pelvic mass.

Our objective was to compare the predictive value of the well-established tumour marker CA125 with the newer tumour markers tetranectin (TN), OVX1 and CASA in distinguishing benign and malignant pelvic masses in women. Participants included 185 women, 19 years or older, with a pelvic mass planned for surgical exploration. Significantly different CA125 levels were found between benign tumours and localised ovarian cancer (OC), advanced OC and other non-OCs. Significantly different TN levels were found between benign tumours and advanced OC (stage III/IV), between benign tumours and other cancers and between all OCs and other cancers. For CASA, significant differences were found between benign tumours and all OCs as well as advanced OC. No significant differences could be demonstrated for OVX1. Significant correlations for the 44 OC patients were found between CA125, TN and CASA. No significant correlations were found for OVX1, possibly because of the method used for collection and handling of serum samples. None of the new markers had any additional predictive value compared to CA125. TN and CASA levels correlated with FIGO stage and could be used to discriminate between benign and advanced OC. However, in comparison to the performance of CA125, the additional discriminative value of TN and CASA was minor.

Adult↗

PubMed2000

Effects of paclitaxel on CA-125 serum levels in ovarian cancer patients.

OBJECTIVE: As in vitro activation of ovarian carcinoma cells in terms of CA-125 secretion by taxanes has been demonstrated, we were interested in whether taxanes also modulate CA-125 expression in vivo. METHODS: Serum CA-125 was determined immediately before and 24 h after paclitaxel-containing chemotherapy in 53 ovarian carcinoma patients. To test the quality of the analysis methods and the biological variation of untreated patients, serum CA-125 levels of two control groups were analyzed. RESULTS: Median CA-125 concentration was 107 kU/liter 24 h after chemotherapy treatment compared with 99 kU/liter the day before paclitaxel treatment. Changes in CA-125 serum levels observed immediately after paclitaxel treatment were not correlated to treatment response. However, overall change in CA-125 serum concentration was a good predictor of response to paclitaxel containing treatment. Patients achieving a complete or partial response had a significant reduction of median CA-125 levels, whereas tumor progression was associated with increased CA-125 levels. Only for the group of patients obtaining a complete response was a decrease in the median relative CA-125 value observed. CONCLUSION: Paclitaxel-induced modulation of CA-125 expression could not be confirmed in vivo.

Adult↗

PubMed1999

Epitope mapping and affinity estimation of 83 antibodies against prostate-specific antigen.

Eighty-three antibodies submitted to the ISOBM TD-3 Workshop on prostate-specific antigen (PSA) were characterized by cross-inhibition studies, immunometric assay and affinity estimation with free or complexed PSA (PSA-alpha1-antichymotrypsin, PSA-ACT). Nine antibodies did not bind PSA or PSA-ACT when coated onto microtiter plates or in solution. Another 3 antibodies bound the antigens only when in solution and were therefore omitted from the cross-inhibition experiments. Dissociation constants (Kd) were estimated from the concentration of free antibody needed to achieve half-maximal binding of the antigen. Kd values for PSA and PSA-ACT ranged from 2 x 10(-12) to >10(-8) mol/l. Antibodies were classified into 6 main groups according to their reactivity. Group 1 comprised 15 antibodies (#25, 26, 33, 68, 73, 77, 78, 80, 85, 209, 213, 216, 223, 230, and 262) specific for free PSA. These antibodies had >80% cross-inhibition and showed high affinity for PSA with minimal or no affinity for the PSA-ACT complex. Group 2 comprised antibodies that reacted with both free PSA and PSA-ACT. Three subgroups were defined: group 2a (#40), group 2b (#32) and group 2c (#35, 37, 63, 90, 215 and 226). Group 3a antibodies (#31, 36, 37, 57, 64, 66, 72, 82, 84, 212, 224, 229, 257 and 260) were closely related to those of group 2, with two exceptions in group 3b (#88 and 89). Group 4 contains antibodies with binding patterns similar to those represented by groups 3b and 6b. These antibodies could be divided into two subgroups: group 4a (#30, 38, 51, 217, and 220) and group 4b (#74). Group 5 was more heterogeneous, with distinct inhibition patterns: group 5a (#50, 54, 76, 81,207, and 222); group 5b (#41), and group 5c (#28 and 86). Group 6 antibodies bind epitopes on both free PSA and PSA-ACT, but have epitopes unrelated to those represented in groups 1-3: group 6a contains 15 antibodies (#24, 27, 29, 34, 55, 56, 65, 79, 210, 214, 218, 221, 225, 258 and 261), and group 6b 2 antibodies (#67 and 75). These 6 groups represent the major immunodominant regions, one of which is exposed only on free PSA. Our classification could provide a useful guide in choosing antibodies for future PSA assays.

Antibodies, Monoclonal↗

PubMed1999

The risk-of-malignancy index to evaluate potential ovarian cancers in local hospitals.

OBJECTIVE: To assess the risk-of-malignancy index (a scoring system based on menopausal status, ultrasound features, and serum CA 125) at district hospitals for referral of women with suspected malignant pelvic masses for primary surgery at a central gynecologic oncology unit. METHODS: All seven hospitals in Health Region IV, Norway, agreed to refer women with pelvic masses and risk-of-malignancy indices of 200 or more for centralized primary surgery. In total, 365 women 30 years of age or older, admitted consecutively at the local hospitals, were enrolled in the study from February 1, 1995, to January 31, 1997. RESULTS: Compliance with the study was satisfactory; 84% (65 of 77) of women with risk-of-malignancy indices of at least 200 were referred for centralized primary surgery. Sensitivity and specificity to malignancy were 71% and 92%, respectively, which is in agreement with previous validation of the risk-of-malignancy index in teaching hospital settings. False negatives were due mainly to stage Ia (18 of 24) ovarian cancer, whereas 27 of 28 stage II-IV ovarian cancer cases were identified correctly. CONCLUSION: The risk-of-malignancy index identified women with malignant pelvic masses efficiently. Our study showed the risk-of-malignancy index strategy in a practical setting to be able to centralize primary surgery for advanced ovarian cancer from local hospitals to a subspecialty unit. We recommend the risk-of-malignancy index for detection of patients with advanced ovarian cancer for centralized primary surgery.

Adult↗

PubMed1998

Epitope specificity of 30 monoclonal antibodies against cytokeratin antigens: the ISOBM TD5-1 Workshop.

The epitope specificities of 30 monoclonal antibodies (MAbs) against the most common human cytokeratins. i.e., Nos. 8, 18, and 19, in epithelial cells were investigated in the ISOBM TD-5 Workshop. Seven research groups from universities or companies participated independently in the evaluation of the antibody specificities. The complex assembly of cytokeratins in vivo, with obligatory heterologous dimeric combinations of different cytokeratins from each of the two major groups, comprising together more than 20 different individual cytokeratins, made analysis of the antibody reactivity patterns with isolated single cytokeratins necessary. The concordance of the evaluations was striking and independent of the technologies used. As antigens purified individual cytokeratins, chemically degraded purified cytokeratins, recombinant intact and truncated cytokeratins, as well as specific synthesized shorter peptides were used. In order to elucidate the epitope specificity, reactivity patterns in ELISA assays and immunoblots with partial enzymatic degradation of the antigens were performed. Competitive cross-inhibition experiments between antibodies using antigens and antibodies in all possible combinations were performed with radioimmunometric assays, BIAcore, and ELISA technology. All 30 antibodies could convincingly be classified with regard to target cytokeratin. One MAb (192) had to be deleted due to dual specificities in both isotype and epitope specificity against its target. Six antibodies bound selectively to cytokeratin 8, 14 to cytokeratin 18, and 10 to cytokeratin 19, as demonstrated by using native, recombinant, and synthesized antigens. The immunodominant part of the molecule for all three types of cytokeratins was located in the region of amino acid (aa) 270-400. Out of the six MAbs reactive with cytokeratin 8, four MAbs, i.e., 178, 199, 202, and 206, were reactive with a sequence in the interval aa 340-365, and MAb 191 reacted with a closely related epitope. The remaining antibody, 192, presented dual specificities. At least two closely related major immunogenic epitopes could be identified in cytokeratin 8. In cytokeratin 18 four distinct epitopes could be documented, again with the dominating sequence region 270-429 as target for 10 (181, 184, 186, 188, 189, 190, 193, 196, 198, and 200) out of 14 antibodies. Since MAb 193 is known to react with the M3 epitope, aa 322-342 in cytokeratin 18, this entire group is reactive in the region close to the charge shift, in the middle of the rod 2B region, as shown by competitive binding. The remaining four anticytokeratin 18 antibodies (180, 185, 203, and 205) displayed unique, noncompetitive binding to this filament. Cytokeratin 19, reactive with altogether ten antibodies, displayed two major epitopes, all of them also within the large immunodominant region. MAbs 179, 195, 197, and 204 were reactive with the peptides aa 311-335 also known as the KS 19.1 epitope, and MAbs 182, 183, 187, 194, and 201 bound to peptide aa 346-367, known as the BM 19.21 epitope. One antibody, 231, was selectively reactive with aa 356-370 in cytokeratin 19. A complex pattern of binding specificities comprising at least ten different, noncompetitive epitopes, mainly situated in the rod portion, 2A and 2B, situated close to the charge shift in the rod of all three cytokeratins was documented. Out of the 29 classifiable antibodies, altogether 22 were reactive in this very short region, i.e., from aa 311 to 370 in all cytokeratin filaments. The remaining seven antibodies displayed unique binding properties. The implications of the findings are of significance both for immunohistochemistry and for assaying circulating heterodimeric, partially degraded complexes in patients' blood for tumor marker evaluation.

Amino Acid Sequence↗

PubMed1998

Specificity and affinity of 30 monoclonal antibodies against alpha-fetoprotein.

Twenty-two antibodies with high affinity for AFP could be classified into groups according to five AFP binding regions, designated A-E, based on cross-inhibition studies and immunometric assay combinations. Antibodies in group A (ISOBM TD2 No. in parentheses): H31 (119), AFP-4-F45 (111), 140/5 (117), K51 (99), K52 (110), AFP-200014A (120) and F2 (118) and in group B: A4-4 (98) and AFP-4-F67 (93) were only inhibited by antibodies belonging to the same groups and could be used in immunometric assay combinations with all other antibodies. Groups C, D and E were inhibited by antibodies in adjacent antibody groups and did not form immunometric assay pairs with antibodies belonging to neighboring groups. Group C comprises: K28 (105), A34-B/B5 (101), AFP-4-F111 (95), AFP100025B (121) and K57 (116), group D: E7 (114) and D10 (92) and group E: H219 (115), K6B1 (103), A34-A/D12 (104), C2 (102), C9 (94) and C10 (97). For six of seven antibodies with low binding to labelled AFP, the specificity could not be determined. Two antibodies were not conclusively assigned to any binding region. Antibody 9A12 (109) may be classified into group E based on immunometric assay combinations, but could not be evaluated in cross-inhibition experiments due to low binding to labelled AFP. Antibody 19F12 (100) functioned as a tracer antibody in combination with all other antibodies, but did not bind AFP when used as solid phase antibody. This antibody could therefore represent a unique binding specificity.

Antibodies, Monoclonal↗

PubMed1998

Summary report on the ISOBM TD-6 workshop: analysis of 20 monoclonal antibodies against Sialyl Lewisa and related antigens. Montreux, Switzerland, September 19-24, 1997.

The ISOBM TD-6 Workshop is the first international workshop on monoclonal antibodies against the Sialyl Lewisa (SLea) antigen. Eight research groups participated in a blind study to characterize the epitope binding, relative affinity and performance in immunoradiometric assays, of a panel of 20 monoclonal antibodies. The antibodies were tested against a diverse panel of neoglycoconjugates, purified antigens and human serum pools from gastrointestinal malignancies. Epitope specificities were determined for the majority of antibodies in the panel. Cross-reactivity with related saccharide structures was noted in several antibodies. Overall, the results of the TD-6 Workshop show further development of SLea immunoassays may yield yet more specific assays for the detection and management of gastrointestinal and other malignancies.

Antibodies, Monoclonal↗

PubMed1998

Carcinoma-associated MUC1 detected by immunoradiometric assays.

Fifty-four anti-MUC1 antibodies submitted to the International Society for Oncodevelopmental Biology and Medicine (ISOBM) Workshop (TD-4) were evaluated in immunoradiometric assays, using sera from carcinoma patients and healthy donors. The carcinoma serum pool contained sera from 30 patients with advanced cancer (10 breast, 10 colon, and 10 ovarian). This serum pool contained 696 kU/l MUC1, 770 micrograms/l CEA, and 3,700 kU/l CA 125. The reference serum pool was obtained from 10 healthy women combined with 20 sera from pregnant women, of which half had elevated CA 125 (range 82-254 kU/l). The reference serum pool contained 13 kU/l MUC1, 2 micrograms/l CEA, and 65 kU/l CA 125. The Workshop antibodies were tested both as solid-phase antibodies and as tracer antibodies with the carcinoma serum pool. Twenty-two tracer antibodies and 38 solid-phase antibodies gave at least one combination with > 10% binding of the tracer antibody for a total of 836 combinations. These were tested further with the reference serum pool. Antibodies used as tracers could be separated into three categories: Group 1 antibodies, MF06, MF11, B27.29, MF30, and Ma552, gave mainly 'carcinoma-specific' assays in combinations with the solid-phase antibodies, i.e. binding ratio between carcinoma MUC1 and reference MUC1 > 10. Group 2 antibodies, DF3, 7540MR, A76-A/C7, BC4N154, M38, 7539MR, B12, GP1.4, 232A1, Mc5, and Ma695 gave both 'specific' and 'nonspecific' binding ratios depending on the solid-phase antibody used. Group 3 antibodies, 214D4, BC4E549, E29, BCP8, BC3, and 3E1.2, gave mainly 'nonspecific' combinations, i.e. ratios < or = 10. All antibodies used to capture MUC1 on the solid phase gave both 'specific' and 'nonspecific' combinations depending on the tracer antibody used. Ten antibodies were clearly more efficient as solid-phase capture antibodies; Ma695, B12, M38, GP1.4, 214D4, MF06, B27.29, A76-A/C7, BC3, and KC4. Our findings indicate that the ability to detect 'carcinoma-specific MUC1' cannot be deduced from epitope specificity alone.

Adult↗

PubMed1996

Evaluation of a risk of malignancy index based on serum CA125, ultrasound findings and menopausal status in the pre-operative diagnosis of pelvic masses.

OBJECTIVE: To evaluate the ability of a risk of malignancy index (RMI), based on a serum CA125 level, ultrasound findings and menopausal status, to discriminate a benign from a malignant pelvic mass and to discriminate early stage (Figo Stage I) from Stages II, III and IV of ovarian cancer. DESIGN: A prospective study. SETTING: Department of Gynaecology, Trondheim University Hospital, Trondheim, Norway. PARTICIPANTS: One hundred and seventy-three women, 30 years or older, consecutively admitted between February 1992 and February 1994 for primary laparotomy of a pelvic mass. MAIN OUTCOME MEASURES: The sensitivity, specificity and positive predictive value of serum CA125 level, ultrasound findings and menopausal status, separately and combined into the RMI, to diagnose ovarian cancer. RESULTS: The RMI was more accurate than any individual criterion in diagnosing cancer. Using a RMI cut-off level of 200 to indicate malignancy, the RMI derived from this dataset gave a sensitivity of 80%, specificity of 92% and positive predictive value of 83%. Applying RMI criteria developed by others, the following test performance was found: sensitivity 71%, specificity 96% and positive predictive value 89%. For the Stages II, III and IV of ovarian cancer the sensitivity increased to approximately 90% without any substantial loss in specificity. CONCLUSIONS: The risk of malignancy index is able to correctly discriminate between malignant and benign pelvic masses. It is a scoring system which can be introduced easily into clinical practice to facilitate the selection of patients for primary surgery at an oncological unit.

Adult↗

PubMed1996

Specificity and affinity of 26 monoclonal antibodies against the CA 125 antigen: first report from the ISOBM TD-1 workshop. International Society for Oncodevelopmental Biology and Medicine.

The specificity of 26 monoclonal antibodies against the CA 125 antigen was investigated in two phases of the ISOBM TD-1 workshop. The binding specificity was studied using CA 125 immunoextracted by specific antibodies immobilized on various solid phases, or on the surface of human cell lines. Immunometric assays using all possible antibody combinations were used to study the topography of antibody binding sites on the antigen. We conclude that the CA 125 antigen carries only two major antigenic domains, which classifies the antibodies as OC125-like (group A) or M11-like (group B). One antibody, OV 197, showed binding specificity related to some of the OC125-like antibodies, but was classified into a separate group C. The OC125-like group of antibodies has four subgroups with different binding specificities. These are A1 = OC 125 and K 95, A2 = K 93, A3 = B43.13, and A4 = ZS 33, B27.1 and CCD 247. Binding of nonlabelled OC 125 or K 95 to CA 125 caused a marked increase in binding of labelled OV 197 to the complex. This conformational change was not observed with any other antibody combinations. Antibody B43.13 could form immunometric assay combinations particularly with antibodies of subgroup A4, indicating that the B43.13 epitope is in the periphery of the binding area of OC125-like antibodies. The M11-like group of antibodies is more homogenous with strong cross-inhibition between most antibodies. Only one antibody, ZR 38, would form an immunoassay combination with other M11-like antibodies and thus represents a distinct subgroup. The main group of M11-like antibodies are M 11, ZR 45, MA602-6, K 91, OV 185, K 101, K 90, K 96, K 97, K 102, CCD 242, 145-9, and 130-22. Antibody OV 197 binds to a domain designated C and is unique, as stated above. Antibody pairs from any two of the three groups may be used in immunometric assays. Three antibodies were not studied by complete cross-inhibition due to low affinity (OV 198 and K 100) or lack of material (MA602-1). OV 198 and K 100 are most likely OC125-like and MA602-1 is M11-like. Antibody affinity was estimated with labelled antigen in solution or with antigen absorbed on microtiter wells. Western blot analysis showed staining both in the stacking gel and corresponding to a molecule of 200 kDa. There was a marked difference between the antibodies in their ability to bind to CA 125 immobilized on a membrane. Strongest binding was observed with the M11-like antibodies, particularly M 11, K 96, K 97, MA602-6, 145-9. Antibodies belonging to the subgroup A4 were the only OC 125-like antibodies which reacted well with CA 125 in Western analysis. Digestion of CA 125 with proteolytic enzymes showed it to be particularly sensitive to trypsin cleavage. However, no low molecular weight fragments with preserved immunoreactivity were found.

Animals↗

PubMed1996

Immunohistochemical characterization of 22 monoclonal antibodies against the CA125 antigen: 2nd report from the ISOBM TD-1 Workshop.

We evaluated the immunohistological (IH) characteristics of 22 different antibodies that were submitted for study in the frame of the TD-1 ISOBM Workshop on monoclonal antibodies against CA125. Information on relative affinities and epitope similarities was obtained from a parallel immunochemical study. Antibodies were tested at concentrations of 10 and 1 micrograms/ml on frozen and paraffin sections. Paraffin sections were stained according to the streptavidin-biotin complex protocol, and frozen sections according to a two-step immunoperoxidase technique. Aminoethylcarbazole served as the chromogen. The tissues were from normal proliferative endometrium (formalin-fixed paraffin-embedded) material and clear-cell adenocarcinoma of the ovary (formalin-fixed paraffin-embedded and frozen material). Sections were scored for staining in epithelial cells, basal, apical and diffuse cytoplasmic and in stromal components. Intensity was graded as 1, 2 or 3 for epithelial cells and as -1, -2 or -3 for stroma. The cumulative scores for each antibody expressed the discriminative properties of specific epithelial staining against background. M11 and M11-like antibodies, as well as OC125 and OC125-like antibodies, in general showed good staining results. Although there was a trend for high-affinity antibodies to show higher scores, there was no clear relationship between affinity and staining result. For nine antibodies (ZR45, MA602-1, K102, K94, K90, OV185, K97, K96, OV198), the reactions in paraffin and frozen sections were of similar intensity. Most of these were of low affinity with one exception: antibody ZR45, a rat monoclonal antibody (MAb) which had a high relative affinity. For eight antibodies (M11, K101, MA602-6, ZS33, B27.1, B43.13, K93, OC125), a loss of specific staining was observed in frozen sections. All but two of these antibodies (MA602-6 and OC125) were of high relative affinity. With four antibodies (K91, ZR38, K95, K100), the reverse situation was observed. One (K100) was of low affinity, two (K95 and K91) of high affinity and the fourth (ZR38) was a rat MAb of high affinity. Mainly due to the increased cytoplasmic staining in carcinoma, the reactivity in paraffin sections was less extensive in normal endometrium compared to ovarian carcinoma for the majority of antibodies, irrespective of their affinity or epitope group. The IH characterization of these antibodies may be of help in selecting antibodies with specific properties for further comparative studies. The reactivity of normal endometrium with all useful antibodies makes it a good candidate for standard external IH tissue control.

Adenocarcinoma, Clear Cell↗

PubMed1995

[Preoperative identification of malignancy among women with a pelvic mass. Evaluation of a risk index based on ultrasound findings. CA 125 in serum and menopausal status].

A risk of malignancy index (RMI) based on vaginal ultrasound, the tumour marker CA 125 level in serum, and menopausal status was calculated in 134 consecutive patients with a pelvic mass. 41 patients harboured a malignancy, while in 93 the condition was benign. The specificity according to the presence of a malignancy was 95% using the risk of malignancy index, compared with 78% when ultrasound was used alone, and 78% when CA 125 was used alone. The corresponding sensitivities were 73, 71 and 83% respectively. The majority of patients with a false negative index score had early stage ovarian cancer. Only one of the 21 patients with advanced ovarian cancer had a score below the limit of 200. The use of the risk malignancy index is a convenient method for pre-operative identification of cases of advanced ovarian cancer.

Adult↗

PubMed1995

A sequential binding assay with a working range extending beyond seven orders of magnitude.

A new immunometric sequential binding assay has been developed in which the sample is first reacted with a solid phase binding partner in low concentration, and subsequently with a second binding partner at a higher concentration. The amounts of analyte bound to the two solid phase binding partners are separately measured, thus establishing a double standard curve. There is a shift between the two standard curves along the concentration axis. Thus an unambiguous determination of analyte concentration is obtained, even in the descending region of the curves where the 'hook' effect causes decreasing signal with increasing analyte concentration. A two-particle immunofluorometric assay for AFP based on this principle measured by flow cytometry, resulted in an assay with rapid binding (approximately 2 h), a detection limit of 0.1 kIU/l and a working range (0.3 to > 3 x 10(6) kIU/l) in excess of 7 log10 orders. Assay results compared well with those of an immunoradiometric assay.

Analysis of Variance↗

PubMed1995

Dual analyte assay based on particle types of different size measured by flow cytometry.

Simultaneous flow cytometric assays have been developed for alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG), with internal determination of sample related non-specific binding (NSB). The assays use particles of 7.5, 6.5 and 5.5 microns diameter coated with, respectively, monoclonal antibodies specific for AFP, hCG or an epitope normally not present in serum. The different particle types were identified simultaneously by light-scatter measurements as their specific immunofluorometric responses were determined. The NSB in the simultaneous assay of AFP and hCG was increased by approximately 30% compared to corresponding single analyte assays. The working range of the dual analyte assays was 0.6-2000 kIU/l for AFP and 6-10,000 IU/l for hCG. No significant interference from the presence of the other analyte was observed in the measurement of either AFP or hCG. The 95% confidence interval for the ratio of dual over single analyte assay results was [0.81, 1.11] for AFP and [0.88, 1.16] for hCG.

Acrylates↗

PubMed1995

Alpha-particle radiotherapy with 211At-labeled monodisperse polymer particles, 211At-labeled IgG proteins, and free 211At in a murine intraperitoneal tumor model.

Four different chemical forms of the alpha-particle emitting radionuclide 211At were injected intraperitoneally in mice inoculated intraperitoneally 30 hr in advance with 10(6) cells of the K13 murine hybridoma cell line. The different 211At forms were (a) free 211At, (b) 211At-labeled TP-3 nonspecific monoclonal antibody (211At-TP-3), (c) 211At-labeled human IgG kappa (211At-hIgG kappa), and (d) 211At-labeled monodisperse polymer particles (211At-MDPP). A significantly prolonged survival (P < 0.05) was observed with injected doses down to 7 kBq for the 211At-MDPP, and down to 25 kBq for 211At-hIgG kappa. There were no significant differences in survival between 211At-MDPP, 211At-hIgG kappa, and 211At-TP-3 at the dose level of 200 kBq. The group receiving 250 kBq free 211At per animal had a shorter survival than the three other forms at 200 kBq. The groups treated with 500, 200, and 65 kBq 211At-MDPP had a similar survival. The group given the highest dose of 211At-hIgG kappa (275 kBq) had the highest fraction (50%) of long-term survivors of all groups. Biodistribution measurements and total body scintigrams in mice without tumor revealed that the free 211At was distributed all over the body within 10 min after injection while at 2 hr a high fraction of the 211At-TP-3 and 211At-hIgG kappa was still present intraperitoneally. In conclusion this study indicates that 211At-labeled MDPP and 211At-labeled IgG's may be efficient tools for treatment of intraperitoneal superficial tumor cells and malignant ascites.

Animals↗

PubMed1995

Comparison between soluble tumor necrosis factor receptors and CA125 in peritoneal fluids as a marker for epithelial ovarian cancer.

The levels of the soluble forms of the membrane-bound receptor for tumor necrosis factor (TNF), p55 and p75, were assessed in peritoneal fluid samples from 50 patients with ovarian cancer, from 20 patients operated for benign pelvic masses, and from 26 healthy women undergoing laparoscopy. The 95% cutoff for normal levels were 14.0 and 5.2 ng/ml for p55 and p75, respectively. In patients with active ovarian cancer, elevated levels of p55 and p75 were found in 54 (p55) and 84% (p75) of the patients, and elevated levels were seen in all histologic types. The levels correlated with peritoneal fluid quantity and with stage of disease. Among 20 patients operated for benign pelvic masses, 1 patient had elevated p55 and 8 patients (40%) had elevated p75. The concentration of CA125 in peritoneal fluids showed a 95% cutoff value in healthy individuals of 8.950 U/ml; and elevated CA125 levels were found in 7 patients with ovarian cancer (14%) and in none of the patients with benign masses. The results indicate that in peritoneal fluid, measurement of soluble TNF receptors, and particularly of p75, has an increased sensitivity and accuracy over CA125 in distinguishing ovarian cancer from benign pelvic masses.

Adult↗