Biomedical subjects

A Pihl

Publications and source records attributed to A Pihl.

At least 19 recordsLinked to original sources

PubMed1994

Immunoscintigraphy of bone sarcomas--results in 5 patients.

The feasibility of using the murine monoclonal antibody, TP-1, for clinical immunoscintigraphy was examined in a pilot study involving 5 patients with bone sarcomas. 131I-labelled F(ab')2 antibody fragments were injected in doses of 0.8-1.0 mg (90-130 MBq), and the accumulation of radioactivity was examined by scintigraphy, and assessed by direct measurements on biopsied tumour and normal tissue. One osteosarcoma patient had a primary tumour in the femur, whereas the other 4 had single lung metastases detected by other diagnostic methods. Immunoscintigraphy of the femoral primary was optimally visualised after 22 h. In 2 patients, the method failed to detect lung metastasis, in 1 of the cases possibly related to less than optimal methodological conditions. In 2 other patients, increased accumulation of radioactivity indicated one and three lung tumours, in addition to the single metastasis observed by X-ray and CT scanning, tumours that were later confirmed and removed surgically. The concentration of radioactivity in tumour and normal tissues 44-72 h after antibody injection could be measured in 4 patients. The tumour to blood ratios were in the range of 1.2-4.2, compared to 0.1-0.8 for various normal tissues. The results indicate that immunoscintigraphy with TP-1 antibody fragments have a potential for early detection of lung metastases in patients with bone sarcoma.

Adolescent↗

PubMed1992

Immunotoxins directed against the high-molecular-weight melanoma-associated antigen. Identification of potent antibody-toxin combinations.

To study factors influencing the cytotoxicity of immunotoxins (ITs), we compared the in vitro cytotoxicity of conjugates in which the plant toxin abrin and the bacterial toxin Pseudomonas exotoxin A (PE) were coupled by 2 different procedures to 2 MAbs, 9.2.27 and NR-ML-05, which bind to different epitopes on the melanoma-associated antigen p250. The individual target cell lines differed widely in sensitivity to the different ITs, as assessed by measurement of protein synthesis inhibition. The action of the ITs was highly specific, as the toxicity of abrin and PE conjugates was respectively 20-540 and 2,200-550,000 times higher in antigen-positive cell lines (FEMX, SESX, OHS) than in the antigen-negative line KPDX. The PE conjugates prepared with the 2 different MAbs differed in potency by factors of 16-126 in the target-cell lines, but were consistently more toxic than the abrin ITs. The results demonstrate that the cytotoxicity of ITs varies with the nature of both of its moieties and that optimal results require that toxins and MAbs be matched. Moreover, the 2 coupling procedures affected differentially the binding and potency of some ITs. Each of the 2 toxins was conjugated to a sheep anti-mouse antibody (SAM) and the toxicity of these 2 conjugates was tested in an indirect approach using 9.2.27 and NR-ML-05 as primary MAbs. The results showed that the indirect procedure would have correctly predicted the most potent antibody-toxin pair, indicating that the approach may be valid for selecting suitable combinations of MAbs and toxins for use as direct ITs.

ADP Ribose Transferases↗

PubMed1992

An effective immunomagnetic method for bone marrow purging in T cell malignancies.

An immunomagnetic method was developed to purge human bone marrow of malignant T cells, for use in conjunction with autologous bone marrow transplantation in patients with acute lymphoblastic leukemia and lymphoma. Three monoclonal antibodies anti CD2 (BH1), CD5 (BB8) and CD7 (BF12) were used. In model experiments employing MOLT4 cells it was found that with 50-fold excess of immunobeads relative to antigen-positive cells, the use of each antibody alone resulted in a 3.3-3.6 log tumor cell depletion, as assessed in a sensitive and reproducible clonogenic soft agar assay. When all three antibodies were used in a mixture, a purging efficacy of 5 logs was achieved. Two treatment cycles improved these figures to about 4 logs and more than 5 logs. When MOLT4 cells were mixed 1:10 with fresh bone marrow cells the antibody mixture yielded 3.1 and more than 5 log tumor cell depletion with one and two treatment cycles, respectively. This procedure resulted in only an insignificant reduction of the number of CFU-GM and CFU-GEMM progenitor cells. In two patients autotransplanted with purged marrow, the loss of CFU-GM was 37% and 48%, and no tumor cells could be detected by immunocytochemistry after purging. Rapid and sustained engraftment was achieved and both patients remain in complete remission after more than 20 months.

Antibodies, Monoclonal↗

PubMed1991

Different metastasis patterns of a human melanoma cell line in nude mice and rats: influence of microenvironment.

The metastatic capacity of intravenously injected human FEMX-I melanoma cells in athymic nude mice and rats was compared. Young rats given 1 x 10(6) ascites tumor cells all died of lung tumors with a life span of 50 +/- 10 days (mean +/- SD). In contrast, in accordance with previous findings, only extrapulmonary metastases developed in mice. This host-dependent difference in metastasis pattern permitted studies on the role of factors that may influence the organ specificity of metastases. The tissue distribution of 125I-labeled FEMX-I cells did not differ in the two nude species during the first 12 hours after cell injection. The plating efficiency of FEMX-I cells in soft agar was increased by the addition of conditioned medium prepared from rat lungs, resulting also in a significant increase in colony size. In contrast, conditioned medium prepared from mouse lungs reduced the clonogenic capacity of the FEMX-I cells in a dose-dependent manner. Conditioned media prepared from rat and mouse liver, kidney, and spleen tissues either inhibited or had no effect on colony formation. The results suggest that the unexpected differential metastatic patterns observed in vivo may reflect differences in the presence of growth-modulating paracrine factors in the host lungs.

Animals↗

PubMed1990

Nude rat model for studying metastasis of human tumor cells to bone and bone marrow.

Bone metastases reproducibly developed in nude rats after an injection of LOX human malignant melanoma cells into the left ventricle, with hind leg paralyses appearing in all animals within approximately 2 weeks. Manifest metastases were present exclusively in the skeletal system, predominantly in the lumbar portion of the spine, the long bones, and occasionally in the skull. Intracardially injected 125I-labeled tumor cells and monodisperse microspheres were distributed in parallel to the various tissues. Moreover, because the levels of radioactivity were significantly lower in bone than in lung, kidney, and liver, the pattern of metastases could not be explained solely by hemodynamic factors. In chemotherapy experiments, the survival time of rats given left ventricular injections of LOX cells increased in a dose-dependent manner after the animals were treated with dacarbazine. Researchers may find the model useful for studying the biology of bone metastases and for testing the sensitivity of these lesions to drugs.

Age Factors↗

PubMed1989

A human tumor lung metastasis model in athymic nude rats.

Experimental lung metastases regularly developed in athymic Han:rnu/rnu Rowett rats after i.v. injection of LOX human malignant melanoma cells. When 5 x 10(5) tumor cells were injected into 4-week-old rats, 89% of the animals died of lung tumors, with a mean survival time of 18 days. With 5- and 6-week-old rats, however, the fraction of animals that died decreased to 80 and 46%, with mean survival times of 35 and 38 days, respectively. The number of detectable lung colonies in each animal was about 35 in 5- and 6-week-old animals, compared to nearly 300 in 4-week-old rats. In the latter, a correlation was found between the number of tumor cells injected and the number of detectable lung colonies. The capacity of the LOX tumor to grow s.c. and to form experimental lung metastases was, by and large, similar in young nude rats and in nude mice, and no significant difference in morphology between the different tumors in the two species was seen. A high-resolution radiographic method was used to visualize lung colonies in the nude rats, and single tumors with diameters as small as 2-4 mm could be detected. By this method, for the first time, the effect of chemotherapy on a human tumor growing in a visceral organ of a rodent host could be followed by repeat X-ray examinations, mimicking a situation commonly faced in the clinic. This procedure may prove particularly useful for experimental chemotherapy studies, and may be extended to other human tumors that frequently metastasize to the lungs. Indications were obtained that some host-specific differences in tissue-preferenced growth might exist, a possibility that will be further explored.

Animals↗

PubMed1989

Colony forming ability of human breast carcinomas: lack of prognostic significance.

To study whether colony growth in vitro reflects the prognosis of breast cancer patients, specimens from a total number of 138 patients with primary breast carcinomas were cultivated in the Courtenay-Mills soft agar method. The plating efficiency (PE) values were related to various clinical and histopathological parameters. No significant correlation was found between colony forming ability and menopausal status, histopathology, TNM-status or steroid hormone receptor status. The crude survival of the patients was not significantly correlated to the in vitro growth of the tumours; neither was there any difference in relapse-free survival between patients whose tumours failed to grow in vitro and those having growing tumours (PE greater than 0). A multivariate survival analysis of 115 patients with primary tumours without distant metastases revealed that the PE was not a significant independent prognostic indicator, as it gave no additional prognostic information above that of node and ER status. It is concluded that routine measurement of colony formation in vitro is not warranted in the management of breast cancer.

Adult↗

PubMed1989

Immunomagnetic removal of B-lymphoma cells using a novel mono-sized magnetizable polymer bead, M-280, in conjunction with primary IgM and IgG antibodies.

The efficacy of a novel monosized and magnetizable polymer bead, denoted M-280, in immunomagnetic removal of Rael B-lymphoma cells was compared with that of M-450 beads, previously used in bone marrow purging. The M-280 beads which are smaller (diameter 2.8 microns) and contain less iron than the M-450 beads were coated with polyclonal IgG sheep antimouse (SAM) antibody. The two types of immunobeads were equally efficacious when used together with the mouse monoclonal IgG antibodies HH1 or FN1, giving tumor cell depletions of about 3 logs in one cycle of operation. However, when used together with the primary IgM monoclonal antibodies (MoAbs) AB1 or HH2, the new immunobeads were significantly more efficacious than the M-450 immunobeads. To elucidate the underlying mechanism flow cytometric studies and measurements of the binding of the labeled primary MoAbs to the cellular antigens as well as to the immunobeads were carried out. Competition experiments showed that in the case of IgG MoAbs, the SAM beads bind predominantly to the Fc portion, whereas in the case of the IgM MoAbs, the Fab part plays a relatively greater role in the binding. The results indicate that if M-280 immunobeads are used, IgM MoAbs may profitably be included in antibody cocktails together with IgG antibodies in immunomagnetic purging of B-lymphoma cells. They suggest that in the case of cell bound MoAbs, the epitopes on IgG are more accessible to SAM beads than those of surface bound IgM molecules.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗

PubMed1988

Successful clinical use of an anti-HLA-DR monoclonal antibody for autologous bone marrow transplantation.

It has been widely assumed that anti-HLA-DR antibodies react with pluripotent stem cells and cannot be used in bone marrow purging. We report a case of non-Hodgkin's lymphoma in which an anti-HLA-DR antibody (AB4) was used for immunomagnetic purging and the subsequent autologous bone marrow transplantation resulted in rapid marrow engraftment with no serious complications. The results indicate that the AB4 antibody, which binds to an antigen encoded by the B3 gene of the DR region, can be safely used in the clinic in the purging of bone marrow from patients with AB4-positive tumors (non-T-cell acute lymphocytic leukemia, non-Hodgkin's lymphoma, and some cases of acute myelogenous leukemia.

Adult↗

PubMed1988

Kinetics of uptake and degradation of an abrin immunotoxin by melanoma cells and studies of the rates of cellular intoxication.

The mechanism of action of an abrin 9.2.27 antimelanoma antibody conjugate has been studied in 2 human melanoma cell lines, FEMX and LOX, which differ in sensitivity to the immunotoxin (IT) and to native abrin. The IT, which had been affinity purified before use to remove molecules with exposed gal-binding sites on the toxin B-chain, inhibited cellular protein synthesis at a faster rate in the LOX than in the FEMX cells despite the fact that the LOX cells express less specific antigen and bind less IT to the cell surface. Surface-bound abrin-IT, as well as surface-bound specific antibody, disappeared at equal rates from the cell surface of the 2 cell lines. After binding of labelled IT the disappearance of total cell-associated radioactivity, as well as the appearance of TCA-precipitable and TCA-soluble radioactivity in the incubation medium, occurred at faster rates in the LOX than in the FEMX cells. No free abrin or antibody B-chain complex could be detected in the medium or inside the cells. The results indicate that the different sensitivities of the melanoma cell lines reflect different abilities to process endocytosed IT and to translocate the active A-chain to the cytosol. Experiments carried out in the presence of lactose are interpreted to mean that the A-chain may be translocated to the cytosol by two mechanisms, one involving antigen-antibody interaction and one involving the B-chain, and that the lectin binding site contributes to the B-chain-facilitated mechanism.

Abrin↗

PubMed1988

Expression and characteristics of a novel human osteosarcoma-associated cell surface antigen.

The characteristics of a new osteosarcoma-associated cell surface antigen were studied by means of two murine monoclonal antibodies, TP-1 and TP-3, which were found to bind to two different epitopes on the same antigen, a monomeric polypeptide with a molecular weight of approximately 80,000. Immunohistochemical studies showed that the antigen was present in all osteogenic sarcomas tested, in most cases of malignant fibrous histiocytoma, in two malignant hemangiopericytomas and in a few synovial sarcomas, but not in other main groups of sarcomas and nonsarcomatous malignancies. In normal tissues it was detected only in clusters of cells in the adrenal medulla and in proximal kidney tubules. Also endothelial cells in proliferating capillaries in placenta and in most tumors were stained. The antigen was absent in resting but present in actively proliferating osteoblastic cells. The epitopes were resistant to proteolytic and sugar-cleaving enzymes but sensitive to high temperatures and could not be detected in paraffin-embedded specimens. The tissue distribution and properties of the antigen show that it is different from the sarcoma-associated antigens previously studied. In contrast to previous findings with three other anti-sarcoma monoclonal antibodies, no correlation was found between serum alkaline phosphatase activity and the amount of TP-binding substances in the same sera. Nevertheless, an apparently complex association between alkaline phosphatase and the TP-binding antigen seems to exist. Thus, the Mr 80,000 antigen extracted from an osteosarcoma cell line showed enzyme activity, whereas TP-binding molecules precipitated from patient sera contained alkaline phosphatase activity only in a few of the cases studied. Altogether our data suggest that the antigen defined by the TP antibodies may be a marker of osteoblastic differentiation. The pattern of antigen expression in malignant tumors is unique, inasmuch as the antigen is found selectively in sarcomas and in all 31 osteosarcomas tested.

Adrenal Medulla↗

PubMed1988

Extrapulmonary, tissue-specific metastasis formation in nude mice injected with FEMX-I human melanoma cells.

FEMX-I human malignant melanoma cells, originating from a lymph node metastasis in a patient, uniquely and selectively produced extrapulmonary metastases after i.v. injection of cells prepared from xenografts into adult, nude mice. After a lag time of approximately 50 days, metastases were observed in s.c. sites at the back and front of the neck, and in axilla and inguinal regions. Tumor colony formation in lungs were never detected. The interscapular tumors showed a close relationship to brown fat, partly infiltrating this tissue, whereas the other s.c. tumors seemed to be localized to lymph nodes. Mesenterial and mediastinal lymph node metastases were frequently found, together with retroperitoneal tumors along the spine. The normal cells of the adrenal medulla were often replaced by melanoma cells, whereas the cortical tissue was not affected. The conclusion that FEMX-I cells possess an inherent ability for tissue-specific metastasis formation is supported by the metastatic pattern seen after i.p. and intrasplenic injection, as well as after inoculation of the cells in the footpads of the mice. The relatively slowly growing FEMX-I tumors showed the same differentiated morphology as the patient's tumor, independent of the site of growth and the number of passages in the animals. The FEMX-I tumor was easily established as a cell line in vitro. Such cells showed a strongly reduced metastatic capacity, indicating that the in vitro growth conditions had induced alterations in the FEMX-I cells influencing their ability to form site-specific metastases, changes that were shown to be reversible. It is suggested that structures on the surface of the tumor cells, as well as growth factors in the host tissues, may be of importance for the observed tissue specificity. The FEMX-I melanoma, which, as a human tumor in nude mice, has a unique metastatic pattern, offers possibilities for investigating mechanisms involved in site-specific metastasis formation, as well as for testing effects of antimetastatic, chemotherapeutic, and immunotherapeutic agents against human extrapulmonary micro- and macrometastases.

Animals↗

PubMed1988

New indirect approach to the therapeutic use of immunotoxins.

To improve the applicability of immunotoxins (ITs), we have developed a new two-step indirect procedure. The target cells to be killed are first incubated with cell-specific mouse monoclonal antibodies (MAbs). After removal of excess unbound antibody, the cells are incubated in the presence of lactose with an indirect IT, a conjugate of whole abrin and sheep anti-mouse immunoglobulin (SAM) that binds only to cells having primary mouse MAbs on their surfaces. The SAM-abrin IT is affinity purified before use to remove molecules with exposed B-chain-binding sites; it was nontoxic in the absence of the specific mouse MAbs, demonstrating the specificity of the two-step method. We compared the indirect approach, using four different primary MAbs, with the conventional method, in which abrin is coupled directly to the mouse MAbs. In three human cell lines--the melanoma line FEMX, the Burkitt cell line Rael, and the leukemia cell line KM3--the cell kill, measured by a clonogenic assay, was consistently greater with the indirect than with the direct method. In the melanoma and Rael cells, the indirect method gave a higher cell kill than even native abrin. With a mixture of two different antibodies an additive effect was observed with the indirect but not with the direct method. The new approach greatly simplifies the therapeutic application in vitro of ITs, because it permits the use of different primary antibodies, singly or in mixtures, in conjunction with only one or a few general indirect ITs. In efforts to further improve the usefulness of the indirect method, other indirect ITs containing different toxin moieties are being examined. The possibility of employing the indirect principle in vivo is being explored.

Abrin↗

PubMed1988

A new experimental metastasis model in athymic nude mice, the human malignant melanoma LOX.

The human tumor line LOX was established as an s.c. xenograft in nude mice from a lymph-node metastasis of a patient with malignant melanoma. I.v. injection into adult nude mice of single-cell suspensions prepared from xenografts resulted in progressively growing lung tumor colonies that killed the animals. No difference in colony formation was seen between cells taken from lung colonies and s.c. xenografts. An in vitro cell line, LOX-L, was established from lung colonies, and the monolayer cells, detached with EDTA, retained the same ability to form experimental lung metastases. In a total of 14 experiments, 82 of 89 mice receiving 1 X 10(6) viable tumor cells died with a mean survival time of 34.1 +/- 4.8 days. Long-term passaging in vivo and in vitro did not result in any alteration of the lung-colonizing potential of the LOX cells, whereas trypsinization of the cells before i.v. injection reduced lung colony formation. The life span was inversely related to the number of LOX cells injected, permitting estimation of the cell kill caused by chemotherapy. Mice injected i.v. with the LOX cells showed the same relative response to cis-diamminedichloroplatinum (CDDP) and mitozolomide (MZA) as did animals carrying s.c. xenografts. The LOX cells have shown a remarkable stability and similarity to the cells of the patient's tumor with respect to morphology, karyotype and chemosensitivity. The LOX model may be useful for testing effects of therapy on lung micro- and macrometastases, and the activity of antimetastatic agents, as well as for studying mechanisms involved in the metastatic process.

Animals↗

PubMed1988

Sodium thiosulfate fails to increase the therapeutic index of intravenously administered cis-diamminedichloroplatinum (II) in mice bearing murine and human tumors.

Intravenous (i.v.) administration of sodium thiosulfate reduces the toxicity of cis-diamminedichloroplatinum (II) (CDDP). This effect, which allows the use of increased CDDP doses, has been exploited clinically in the intraperitoneal (i.p.) treatment of intraabdominal tumors. Recently, attempts have been made to treat extraperitoneal tumors by concurrent i.v. administration of CDDP and sodium thiosulfate. We have tested this approach in mice bearing systemic L1210 leukemia, s.c. growing Lewis lung carcinoma, C3H mammary carcinoma, and a human sarcoma growing in athymic nude mice. In all cases the antitumor activity of CDDP was substantially reduced in a manner dependent on the thiosulfate dose. Increased doses of CDDP, permitted by reduced toxicity in the presence of thiosulfate, raised the antitumor activity. However, the latter did not exceed that obtained by much lower doses in the absence of thiosulfate. The present experiments in animal models thus fail to support the clinical use of CDDP given i.v. together with its antidote, sodium thiosulfate.

Animals↗

PubMed1988

Cultivation of human breast carcinoma in soft agar. Experience with 237 fresh tumour specimens.

A total of 237 breast carcinomas have been studied with the Courtenay-Mills (C-M) soft agar method. Cell yields and plating efficiencies (PE) were recorded after various enzyme treatments. The highest cell yields and PEs were obtained with the combination of collagenase 0.5%, hyaluronidase 1000 IE ml-1 and DNase 0.1% and an incubation time of 2 h. Eighty percent of the specimens gave greater than 10 colonies, and 60% formed greater than 30 colonies permitting chemosensitivity studies. The C-M method gave significantly higher PEs than the Hamburger-Salmon (H-S) method. Hormone supplements (insulin, oestradiol, progesterone, hydrocortisone) and also reduced agar concentrations (less than 0.3%) gave marginal stimulation of colony formation. In chemosensitivity studies involving doxorubicin, vincristine and 4-OOH-cyclophosphamide, the C-M method gave dose-response relationships without plateaus.

Breast Neoplasms↗

PubMed1988

Predictive chemosensitivity testing in malignant melanoma: reliable methodology--ineffective drugs.

A retrospective and a prospective trial were carried out in patients with malignant melanomas to investigate the predictive value of an in vitro chemosensitivity assay based on the Courtenay and Mills soft agar cultivation method. Evaluable in vitro chemosensitivity data for the three agents DTIC, CCNU, and vinblastine were obtained in 153 cases. In the retrospective study in which the patients received chemotherapy without prior knowledge of the test results, 50 in vitro/in vivo correlations (40 patients) were made, and in the prospective study, where patients received the single agent most active in vitro, 55 correlations (45 patients) were performed. In both studies the sensitivity of the test (the ability to identify patients who will respond to chemotherapy) was approximately 100% and the specificity (the ability to identify patients who will not respond) was 87-98%. Depending on whether 'no change' and 'mixed response' were classified as sensitivity or resistance, the predictive value of a negative test was approximately 100% and that of a positive test 37.5-87.5%. The response rate was low in both series, and although it was somewhat higher in the prospective than in the retrospective trial, the difference was not significant. The median survival time was not significantly different in the two treatment series. We conclude that the chemosensitivity assay here used is reliable and has predictive value, but that the chemotherapeutic agents currently available for treatment of melanoma are too ineffective to warrant routine use of the assay in this disease.

Dacarbazine↗

PubMed1988

An immunocytochemical method for assaying oestrogen receptors in breast cancers. A comparison with the steroid binding assay.

The presence of oestrogen receptors was studied in 105 human breast carcinomas using monoclonal antibodies (Abbott ER-ICA kit). The oestrogen receptors of neoplastic cells were semiquantitatively measured and correlations were made to receptor values determined by a dextran-coated charcoal (DCC) steroid binding assay and to histological grade. Immunoreactive cells were found in about 2/3 of the tumours. Usually only a fraction of the cells within each tumour were immunoreactive, and the staining intensity varied among different cells. In general, well differentiated tumours had a greater proportion of immunoreactive cells than poorly differentiated ones. In most cases (65/98) a good agreement was found between the ER-ICA method and the DCC assay. However, in 33 cases discrepancies were demonstrated.

Breast Neoplasms↗