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J M Esteban

Publications and source records attributed to J M Esteban.

53 records · Page 3Linked to original sources
PubMed1989

Comparison of methods for the generation of immunoreactive fragments of a monoclonal antibody (B72.3) reactive with human carcinomas.

Immunoglobulin fragments, whether of polyclonal or monoclonal antibodies, offer a number of advantages over the intact immunoglobulin. The generation of immunoreactive fragments from monoclonal antibodies (MAb) is not always a straightforward task. Both pepsin and papain can be used to digest MAb to a bivalent molecule with a Mr of 100,000. However, pepsin pepsin digestions does not always result in immunoreactive fragments and a stable consistent product by papain digestion is often difficult to obtain. MAb B72.3 is an example of both situations. MAb B72.3 reacts with a glycoprotein (TAG-72) with a molecular weight greater than 10(6). MAb B72.3 has been shown to exhibit a high degree of selective reactivity with colon, breast and ovarian carcinomas and has been used for radioimmunodiagnosis in model systems and in clinical trials. A third enzyme, bromelain, in the same family of sulfhydryl proteases as papain, has been used to generate a fragment of MAb B72.3, with a Mr of approximately 100,000. The bromelain-generated fragment of MAb B72.3 retained 100% immunoreactivity as measured in competitive solid-phase radioimmunoassays and could be generated with consistent results from one preparation to another. Both the bromelain- and papain-generated fragments were radiolabelled with 125I without significant loss of the MAb's reactivity to tumor extracts. Differences were observed between the bromelain- and papain-generated fragment when compared in vivo. Fragmentation of MAb B72.3 with bromelain has yielded a superior bivalent fragment for radioimmunolocalization.

Animals↗
PubMed1989

Effect of yttrium-90-labeled anti-carcinoembryonic antigen monoclonal antibody on the morphology and phenotype of human tumors grown as peritoneal carcinomatosis in athymic mice.

Grossly visible peritoneal carcinomatosis resembling that seen in man was produced in athymic mice 7 days after intraperitoneal injection of 8 x 10(5) cells of the carcinoembryonic antigen (CEA)-producing human colon carcinoma cell line LS174T. The mice received intraperitoneal injections of 40 to 160 microCi of yttrium-90 (90Y)-labeled anti-CEA monoclonal antibody (MAb). When the mice were killed 12 days after injection, a significant inhibition of tumor growth, ranging from 40% to 95%, was observed in the treated animals when compared to the growth of tumors in the untreated animals (P less than 0.001). No mortality secondary to the therapy was seen. The bone marrow was depleted significantly at the higher doses of labeled MAb, but total recovery was observed 4 weeks after treatment. Histologically, the treated tumors showed extensive radiation effects early in the posttherapy period and massive necrosis at later times. Minute foci of viable tumor remained in the periphery. New tumor outgrowths with histologic features similar to those in the untreated controls began to appear 3 weeks after therapy. The CEA expression of the treated tumors was similar to that of the untreated controls during the early posttreatment period, diminishing progressively as the tumors became necrotic. Newly grown tumor nodules in the treated animals lacked significant CEA expression both initially and at later times. Our studies suggest that therapy with 90Y-anti-CEA MAb therapy results in selection of tumor clones lacking CEA, and that a single large dose of 90Y-MAb should be more effective than multiple fractions of smaller doses.

Animals↗
PubMed1989

Prolongation of survival of nude mice bearing human colon cancer. Treatment with yttrium 90-labeled anti-carcinoembryonic antigen antibody.

Nude mice bearing diffuse intraperitoneal carcinomatosis of the human colon cancer cell line LS174T were treated with an anti-carcinoembryonic antigen monoclonal antibody (MAB) that was labeled with yttrium 90 (90Y-ZCE025). Control animals were either untreated or treated with nonspecific 90Y-MAB (90Y-96.5c). The median survival (MS) for untreated animals was 26 days. The MS for specific and nonspecific therapy that consisted of 120 microCi of 90Y-MAB was 69 and 34 days, respectively. No significant improvement in the MS was observed with a second 120-microCi administration of 90Y-MAB given two weeks later. A decreased MS was observed with 80 microCi of 90Y-MAB given every four days for three cycles. In each category, specific therapy had a significant advantage over nonspecific therapy in increased effectiveness and decreased toxicity. The 90Y-ZCE025 therapy gave an increased life span of almost 200%. The therapeutic effects with different dosing regimens have important implications for treatment planning.

Animals↗
PubMed1987

Quantitative analyses of selective radiolabeled monoclonal antibody localization in metastatic lesions of colorectal cancer patients.

We have previously demonstrated, using in vitro assays, a high degree of selective binding of monoclonal antibody (MAb) B72.3 for carcinomas of the colon, ovary, and breast versus normal adult tissues using in vitro assays. We report here a demonstration of selective tumor localization in colorectal cancer patients of i.v. administered 131I-labeled MAb B72.3 immunoglobulin G prior to surgery. Radiolocalization indices (RI) were obtained by direct analyses of biopsy materials (i.e., cpm of 131I-labeled MAb per g of tumor versus cpm per g of normal tissues). Using as a "positive" localization, RI of 3 times greater than normal tissue (i.e., RI greater than 3.0), tumor lesions in various sites from 17 of 20 patients scored positive. In eight of these patients, all tumor lesions demonstrated RIs of greater than 3, while in five patients RIs of some lesions were greater than 10 and as high as 30 to 46. Seventy % (99 of 142) of tumor lesions showed RIs of greater than 3, while only 12 of 210 histologically confirmed normal tissues examined showed RIs of greater than 3. These tissues, moreover, were either adjacent to tumor or draining tumor masses, or, as in the case of two patients, apparently due to high levels of circulating immune complexes that were deposited in the spleen. Positive gamma scans (confirmed at surgery) were observed in 14 of 27 patients. An isotype-identical control immunoglobulin G was coinjected and showed RIs considerably lower than that of B72.3. No toxicity or adverse reaction was observed with either MAb. These studies are among the most comprehensive to date concerning the definition of the actual delivery of radiolabeled MAb to carcinoma lesions versus a wide range of adjacent and distal normal tissues and lead the way for other diagnostic and potential therapeutic applications of this antibody either alone, or in combinations with other monoclonal antibodies.

Antibodies, Monoclonal↗
PubMed1987

Quantitative and qualitative aspects of radiolocalization in colon cancer patients of intravenously administered MAb B72.3.

Monoclonal antibody (MAb) B72.3 has been previously shown, by in vitro assays, to have a high degree of specificity for carcinomas of the colon, ovary and breast versus normal adult tissues. B72.3 IgG was labelled with 131I and injected i.v. into 20 patients with known or suspected colorectal cancer. All patients subsequently underwent surgical exploration, with tumor and selected normal tissues removed for staging purposes. The selective localization of 131I-MAb B72.3 IgG was demonstrated in biodistribution studies in which the % ID/g of each tumor was compared with that of the normal tissues, thus providing a relative RI for each lesion. Of the tumor lesions, 70% (99/142) had an RI of at least 3 (i.e., 3 times greater uptake per gram than normal tissues), and 31% of the tumor lesions had RIs of over 10. Only 12 of 210 (6%) histologically normal tissues had RIs of greater than 3; either these tissues were adjacent to or draining tumor masses or, as in the case of 2 patients, the high RI values were apparently due to deposition of immune complexes in the splenic tissues. Several parameters were studied to determine factors that might influence MAb localization. Whereas tumors of all histologic types localized the MAb, 31% of the well-differentiated mucinous carcinomas displayed tumor-to-normal ratios greater than 10, while less than 5% of the lesions of other tumor types demonstrated similar localization. The expression of the antigen (TAG-72) detected by MAb B72.3 in these tumors, as studied by immunohistochemical techniques using tissue sections, did not always correlate with the outcome of the MAb distribution. No differences in MAb uptake were observed among the carcinoma lesions from numerous anatomic locations, demonstrating the ability of i.v. administered B72.3 to reach all the tumor sites. Furthermore, autoradiographic studies of tumors showed good penetration of the MAb into the medial areas of the tumors, regardless of their size.

Adolescent↗
PubMed1987

Therapy of peritoneal carcinomatosis of human colon cancer xenografts with yttrium 90-labeled anti-carcinoembryonic antigen antibody ZCE025.

The present study was undertaken to determine whether an anti-carcinoembryonic antigen (CEA) monoclonal antibody (MAB), labeled with the potent beta emitter yttrium 90, could alter the growth of diffuse intraperitoneal carcinomatosis of colon cancer. Nude mice bearing the CEA-producing human tumor line LS174T received therapy with the anti-CEA MAB ZCE025 90Y. Animals were evaluated 12 days after therapy. Untreated animals had a mean (+/- SEM) tumor burden of 3.99 +/- 0.10 g, while animals treated with ZCE025 90Y had 0.29 +/- 0.04 g present. This decrease was significant compared with the 1.31 +/- 0.16 g of tumor present in animals treated with a 90Y-labeled nonspecific antibody 96.5c. The therapeutic effects seen with ZCE025 90Y suggest a potentially useful role for 90Y-labeled anti-CEA MABs in the treatment of gastrointestinal carcinomatosis.

Animals↗
PubMed1987

Radioimmunotherapy of athymic mice bearing human colon carcinomas with monoclonal antibody B72.3: histological and autoradiographic study of effects on tumors and normal organs.

Monoclonal antibody (MAb) B72.3 has been linked successfully to several radionuclides forming stable complexes and analyzed in vitro and in vivo without significant loss of its immunoreactivity. Previous studies have demonstrated that radioiodinated B72.3 can selectively bind to human colorectal carcinomas grown in athymic mice. The same successful localization has been obtained more recently in clinical trials in patients with metastatic colorectal carcinomas. The high degree of selective binding of this MAb has led us to investigate its potential as a radioimmunotherapeutic agent. Athymic mice bearing human colon carcinoma xenografts were injected with either 300 or 500 microCi of 131I-B72.3 IgG to assess the effect o the radiolabeled MAb on the tumor growth as well as potential toxic side effects in vital organs. In mice treated with the 131I-B72.3 IgG, a marked inhibition of the growth of the human colon carcinoma xenografts was noticed in comparison with control mice injected with PBS or control mice that received unlabeled B72.3 IgG. The tumors from these control mice weighed 2.7 to 3.7 times more than the tumors from the treated mice at 17 days post-inoculation of the radiolabeled MAb. Autoradiographic studies demonstrated a heterogeneous distribution of radioactivity throughout the tumor mass at 11 days post-administration of MAb. With time, the periphery of the tumor contained significantly less radioactivity than the medial areas composed of predominantly nonviable tissue; these findings suggest that the more biologically active peripheral tumor zones, with higher mitotic rates, could have partially escaped the radiation effect of the single dose administered. The tumor cells could have continued dividing when the levels of circulating radiolabeled monoclonal antibody had decreased. Toxicity was readily evident in the mice injected with the high-dose regimen (500 microCi), with confirmed bone marrow aplasia that proved lethal for 2 of 10 animals. The lower dose (300 microCi) resulted in a bone marrow suppression of approx. 50% of the cells, which proved to be non-lethal. The tumors in the treated mice showed extensive necrosis caused by the lethal dose of 131I-B72.3 that irreversibly damaged the cells. Radiation-induced terminal differentiation of cells was also found as manifested by the drastically decreased mitotic count (0-2 vs. 12-14 per 10 high power fields seen in control tumors) in treated animals.

Adenocarcinoma, Mucinous↗
PubMed1987

Radiolabeled monoclonal antibody B72.3 localization in metastatic lesions of colorectal cancer patients.

We have previously demonstrated a high degree of selective binding of monoclonal antibody (MAb) B72.3 to carcinomas of the colon, ovary, and breast in contrast to normal adult tissues using in vitro assays. In this report we demonstrate selective tumor localization in colorectal cancer patients after intravenously administering 131I-labeled MAb B72.3 IgG. Radiolocalization Indices (RI) (i.e. cpm 131I-labeled MAb per gram of tumor vs cpm per gram of normal tissues), were obtained by direct analyses of biopsy materials. Using an RI of greater than or equal to 3 as a positive localization, tumor lesions in various sites from 17/20 patients scored positive. In eight of these patients, all tumor lesions demonstrated RIs of greater than 3, while in five patients RIs of some lesions were greater than 10 and as high as 30-46. Seventy percent (99/142) of the tumor lesions showed RIs of greater than 3, while only 12 of 210 histologically confirmed normal tissues examined showed RIs of greater than 3. These tissues were either adjacent to the tumor or the draining tumor masses or, as in the case of two patients, was caused by high levels of circulating immune complexes that deposited in the spleen. Positive scintigraphic images (confirmed at surgery) were observed in 14/27 patients. No toxicity or adverse reactions were observed with either MAb. These studies provide absolute quantitative analyses of the actual delivery of radiolabeled MAb to carcinoma lesions vs a wide range of adjacent and distal normal tissues and establishes the means for other diagnostic and potential therapeutic applications of this antibody alone, or in combinations with other monoclonal antibodies.

Antibodies, Monoclonal↗
PubMed1987

Intraoperative diagnosis of breast lesions. Comparison of cytologic with frozen section technics.

A retrospective double-blind examination of the cytologic smears and frozen section tissue slides from 140 lesions of the breast was performed in order to assess the diagnostic accuracy of each method. The cases with diagnostic errors were reevaluated to define the pitfalls encountered in the intraoperative diagnosis of breast lesions by both methods. Results with the cytologic technics are more variable than with frozen sections, but when read by experienced observers the smears are as accurate as frozen sections and have the additional advantages of rapidity, sparing of tissue for other studies, better correlation with fine-needle aspiration cytologic results, and more complete sampling of large or multiple specimens. The authors recommend that intraoperative cytologic examination be employed routinely in breast diagnosis, initially always in conjunction with frozen section examination but eventually in many cases as an alternative technic.

Adenocarcinoma, Mucinous↗
PubMed1987

New method for the chelation of indium-111 to monoclonal antibodies: biodistribution and imaging of athymic mice bearing human colon carcinoma xenografts.

B72.3, a murine monoclonal antibody (MAb) that reacts with 85% of human colon carcinomas as well as other epithelial neoplasias, was labeled with 111In using four chelating agents: 1-(p-isothiocyanatobenzyl)-DTPA (SCN-Bz-DTPA), isobutylcarboxycarbonic anhydride (MA-DTPA), cyclic anhydride (CA-DTPA), and 1-(p-isothiocyanatobenzyl)-ethylenediaminetetraacetic acid (SCN-Bz-EDTA). Comparative biodistribution and imaging studies were performed in athymic mice bearing human colon carcinoma xenografts (LS-174T). Tumor uptake of radiolabel was very similar between the chelates (30% ID/g) and tumors were identified in scintigraphic images with all the chelate-antibody complexes. The uptake by normal organs, especially the liver, was greater for MA-DTPA, CA-DTPA, and SCN-Bz-EDTA chelate-B72.3 IgG (1.3:1 to 2.5:1) in comparison to that found with the B72.3-SCN-Bz-DTPA (approximately 5:1) and abdominal organ, and uptake was very prominent on imaging with these chelate-MAb complexes but was virtually absent in the mice injected with B72.3-SCN-Bz-DTPA. Purification of the MAb-chelate complex by Sephadex G-50 chromatography followed by HPLC using a TSK-3000 column provided better subsequent biodistribution and also resulted in clearer images as compared to MAb chelate complexes purified by less rigorous purification protocols. We conclude that the 111In-SCN-Bz-DTPA complex is superior, at least when bound to MAb B72.3, to other chelate-complexes currently in use.

Animals↗
PubMed1986

Fine needle aspiration in the treatment of ganglion cysts.

Twenty-eight ganglion cysts in 21 patients were diagnosed by fine needle aspiration (FNA) in the Cytopathology Service of The George Washington University Medical Center from January 1979 to December 1984. Twenty-four of these were aspirated by a pathologist. One patient had two ganglions. Seven of the 21 patients had recurrences and six were reaspirated. In five of those patients the cysts never attained their original size or interfered with function. Follow-up ranged from three to 71 months. Based upon our experience, we believe that FNA is a simple, fast, effective, nontraumatic, inexpensive method of treating ganglion cysts.

Adolescent↗
PubMedDate not supplied

Improved direct epifluorescent filter technique for rapid bioburden control in intravenous solutions.

Epifluorescence microscopy of the microcolonies obtained after filtration of a deliberately contaminated intravenous solution, was used for the rapid detection and enumeration of the bacteria. The technique is adequate for the test of low volume solution (with low contamination). Also it allows one to detect a single colony forming unit (c.f.u.)/mL, with great correlation between fluorescence counts and pour plate colony counts; the morphology of microcolonies is typical for most of the microorganisms and it allows a primoidentification (for a trained analyst).

Acridine Orange↗
PubMedDate not supplied

Immune complexes in epidemic (type A) hepatitis. Detection by three methods using laser nephelometry.

Thirty-eight children with acute epidemic hepatitis (Type A) and 22 children in "contact" with the disease, 5 of whom subsequently developed hepatitis, were studied. Three technics based on laser ray nephelometry were employed to investigate the presence of circulating immune complexes. Our results indicated that circulating immune complexes are present in the serum during the course of epidemic hepatitis. These were demonstrated in 79% of the patients. The capacity to fix complement diminishes as the disease evolves toward the convalescent phase. We also detected a similar percentage of immune complexes (80%) in the patients during the incubation period. In the subjects in "contact" with the disease who subsequently did not develop hepatitis, the immune complexes were shown to have a greater capacity to fix complement, and the percentage of immune complexes present was higher (94%). The specificity of the immune complexes was verified by correlating the antivirus A antibody activity with the percentage of C4 in the precipitates obtained by polyethylene glycol (3.5%).

Adolescent↗