Recombinant antibodies for environmental analysis

Initial steps of antibody engineering in the late eighties revolutionized the technology of antibody production, particularly in the area of immunotherapy and diagnostics. Hallmarks that seemed to be out of reach for a long time are now the state of the art, e.g. tailoring of antibodies to match particular needs or by-passing immunization by use of antibody libraries. Despite the apparent benefits of recombinant antibody technologies, this field has been opened up hesitantly for other applications. This review addresses the development of recombinant antibody synthesis in environmental analysis. Examples are given of the molecular evolution of pesticide antibodies and their application for the analysis of real samples.

Cross-section measurement of charged-pion photoproduction from hydrogen and deuterium

We have measured the differential cross section for the gamman-->pi(-)p and gammap-->pi(+)n reactions at theta(c.m.)=90 degrees in the photon energy range from 1.1 to 5.5 GeV at Jefferson Lab (JLab). The data at E(gamma) greater, similar 3.3 GeV exhibit a global scaling behavior for both pi(-) and pi(+) photoproduction, consistent with the constituent counting rule and the existing pi(+) photoproduction data. Possible oscillations around the scaling value are suggested by these new data. The data show enhancement in the scaled cross section at a center-of-mass energy near 2.2 GeV. The cross section ratio of exclusive pi(-) to pi(+) photoproduction at high energy is consistent with the prediction based on one-hard-gluon-exchange diagrams.

Q2 evolution of the generalized Gerasimov-Drell-Hearn integral for the neutron using a 3He target

We present data on the inclusive scattering of polarized electrons from a polarized 3He target at energies from 0.862 to 5.06 GeV, obtained at a scattering angle of 15.5 degrees. Our data include measurements from the quasielastic peak, through the nucleon resonance region, and beyond, and were used to determine the virtual photon cross-section difference sigma(1/2)-sigma(3/2). We extract the extended Gerasimov-Drell-Hearn integral for the neutron in the range of four-momentum transfer squared Q2 of 0.1-0.9 GeV2.

Development of ELISA technique for the analysis of atrazine residues in water

A highly sensitive enzyme immunoassay is described for the detection of atrazine residues in water. Atrazine derivative was conjugated to Bovine Serum Albumin (BSA) to obtain an immunizing antigen and to Horseradish Peroxidase enzyme (POD) to obtain a marker for immunoassay. The formation of these conjugations was confirmed by UV spectroscopy as well as by gel-electrophoresis. Polyclonal antibodies were raised in rabbits by immunization with an atrazine-BSA conjugate containing 29 atrazine residues per BSA molecule. An ELISA on microtitration plates was optimized with peroxidase-atrazine conjugate. The middle of the test (50% B/Bo) was found to be at 90 ng/l, which is well below the maximum concentration permitted by the EC guidelines for drinking water. Detection limits for atrazine of about 1 ng/l could be reached. The assay did not require concentration or cleanup steps for drinking or ground water samples. Validation experiments showed good accuracy and precision. No cross-reactivities were shown by other s-triazines like terbutryn, ametryn, terbuthylazine, des-isopropylatrazine, and de-ethylatrazine except hydroxyatrazine. The latter was present at very low levels that can be calibrated/standardized before analysis or it may be considered as leftover residues of atrazine. Based on these results, it is suggested that this test can be applied to obtain fairly accurate results for atrazine concentration in water samples from different sources.

Advantages of glutamate dehydrogenase as a blood biomarker of acute hepatic injury in rats

In a recent study in rats, alanine aminotransferase (ALT), the preferred plasma biomarker of hepatocellular injury in rats, was ineffective at detecting marked hepatic necrosis produced by acetaminophen (Human and Experimental Toxicology 19, 277-83, 2000). In contrast, glutamate dehydrogenase (GLDH) was markedly elevated. Accordingly, these enzymes were comprehensively evaluated as plasma biomarkers of hepatocellular injury in rats using several other models of hepatic injury, including partial hepatectomy and exposure to methapyrilene, dexamethasone, cyproterone, isoniazid, lead nitrate, and Wyeth-14643. Other enzymes also evaluated were aspartate aminotransferase (AST), sorbitol dehydrogenase (SDH), and the hepatobiliary marker alkaline phosphatase (ALP). Compared to plasma ALT increases, plasma GLDH increases were up to 10-fold greater, up to 3-fold more persistent, and occurred at times following hepatocellular injury when plasma ALT was not increased. Plasma GLDH activity was not inhibited by the test compounds, whereas ALT was substantially inhibited by both isoniazid and lead nitrate. While plasma GLDH activity was unaffected by induction, ALT was induced by cyproterone and dexamethasone, and ALP was induced by Wyeth-14643 and partial hepatectomy. GLDH was concluded to be a more effective biomarker of acute hepatic injury than ALT, AST, SDH or ALP in the rat, based primarily on the large increase following hepatocellular injury, prolonged persistence in the blood following injury, high sensitivity for detection of injury (including pre-necrotic injury), high tissue specificity, and lower susceptibility to inhibition or induction.

[Management of biliary complications after orthotopic liver transplantation]

In this retrospective analysis we report our results after liver transplantation regarding biliary complications (bc) and the effectiveness of endoscopic therapy. In the last 4 1/2 years we found 13 biliary leaks (7 in combination with a stenosis, 3 at the T tube insertion site), 9 biliary stenosis, 3 papillary stenosis, 2 biliary aggregates and one case of ischemic type biliary lesion, resulting in an overall complication rate of 30%. 10 (36%) "bc" could be treated successfully endoscopically, whereas 8 (32%) patients are still under observation with an endoprosthesis in the biliary tract. 10 endoscopic trials were without the desired effect, requiring a surgical reintervention. In 4 cases a thrombosis of the hepatic artery was responsible for the unwanted course.

Engineering receptors and antibodies for biosensors

Biosensor sensitivity and selectivity depend essentially on the properties of the biorecognition elements to be used for analyte binding. Two principally different applications are considered, (1) effects monitoring with biological components as targets for bioeffective substances, among them endocrine disruptors; and (2) immunochemical analysis employing antibodies as binding proteins for a wide variety of analytes such as pesticides. Genetic engineering provides an elegant way not only for providing unlimited amounts of biorecognition molecules but also for the alteration of existing properties and the supplementation with additional functions. Instrumental applications were carried out with the optical sensor BIAcore. The first example deals with the characterization of receptors. For this purpose, the human estrogen receptor alpha was used. Binding studies were carried out with natural as well as xenoestrogens. An equilibrium dissociation constant K(d) of 2.3x10(-10) (M) was derived for 17beta-estradiol. A competition assay was performed with a bovine serum albumin (BSA)-17beta-estradiol conjugate, immobilized at the optical sensor surface, and the free estrogen. The signals obtained represent estradiol equivalents. This format was transferred to a microplate-based enzyme-linked receptor assay. It reached a detection limit of 0.02 microg l(-1) 17beta-estradiol and proved suitable for the detection of natural and synthetic estrogens as well as xenoestrogens in field studies. The second example is targeted at kinetic and affinity measurements of recombinant antibody fragments derived from antibody libraries with s-triazine selectivities. Different strategies for the synthesis of antibody fragment libraries, followed by the selection of specific antibody variants, were examined. An antibody library was derived from a set of B cells. Chain shuffling of the heavy and light chains provided the best binders. An enzyme linked immunosorbent assay (ELISA) was achieved for atrazine with an IC(50) of 0.9 microg l(-1) and a detection limit of 0.2 microg l(-1). The close relations between the optimization of recombinant antibodies by evolutionary strategies and genetic algorithms are considered.

Antibody-based diagnostic and therapeutic innovations for human cancer

As adjuvants, antibody-based diagnostic and therapeutic innovations can potentially decrease morbidity and mortality associated with many human malignancies. Current strategies employing genetically modified constructs may improve tumor penetration and increase versatility.

[Surgical therapy of inflammatory bowel diseases: ulcerative colitis--diverticulitis. Surgical choices in diverticulitis--conventional or laparoscopic surgery?]

There are no prospective randomized studies available to decide which surgical approach should be superior to treat sigmoid diverticulosis. Analysis of clinical studies evaluating laparoscopic or conventional surgery are presenting results as follows: for elective surgery morbidity ranges between 12-20% and mortality rates between 0-2% indicating comparable complication rates. For emergency operations only data from open surgery are available, with morbidity of 33-57% and mortality rates of 7-16%. Advantages of conventional approach are availability, reliability of the surgical technique and there is no patient selection required. Laparoscopic access may offer superior patients comfort and reduce cost, length of hospital stay and resocialisation. It remains to be proven, which approach may be the option of choice in the future, while this surgical technique is still developing.

Precision measurement of the spin-dependent asymmetry in the threshold region of 3He(e, e')

We present the first precision measurement of the spin-dependent asymmetry in the threshold region of 3He(e,e') at Q2 values of 0.1 and 0.2 (GeV/c)2. The agreement between the data and nonrelativistic Faddeev calculations which include both final-state interactions and meson-exchange current effects is very good at Q2 = 0.1 (GeV/c)2, while a small discrepancy at Q2 = 0.2 (GeV/c)2 is observed.

Phase II trial of the anti-G(D2) monoclonal antibody 3F8 and granulocyte-macrophage colony-stimulating factor for neuroblastoma

PURPOSE

To describe oncolytic effects of treatment with anti-G(D2) monoclonal antibody 3F8 plus granulocyte-macrophage colony-stimulating factor (GM-CSF) in patients with neuroblastoma (NB).

PATIENTS AND METHODS

Patients were eligible for 3F8/GM-CSF if intensive therapy had not eradicated potentially lethal NB. One cycle consisted of GM-CSF (subcutaneous bolus) on days 1 through 5, 11, and 12, and GM-CSF (2-hour intravenous [IV] infusion) followed after a 1-hour interval by 3F8 (1.5-hour IV infusion) on days 6 through 10 and 13 through 17. GM-CSF was dosed at 250 microg/m(2)/d on days 1 through 7 and at 500 microg/m(2)/d on days 8 through 17. 3F8 was dosed at 10 mg/m(2)/d (100 mg/m(2)/cycle). 3F8 was given with an opiate and an antihistamine. Patients without progressive disease (PD) or elevated human antimouse antibody titers could be treated again beginning 3 weeks after completion of a cycle.

RESULTS

Among 19 patients treated for NB resistant to induction therapy, 12 of 15 had complete remission (CR) of bone marrow (BM) disease, and three others who had less than partial responses achieved prolonged progression-free survival (one remains on study at 21+ months, two had PD at 12 and 17 months). Among patients treated for recurrent NB resistant to retrieval therapy, five of 10 had CR in BM. The 15 patients treated for PD fared poorly, although two had scintigraphic findings suggestive of a short-term response. Side effects were limited to readily manageable pain and, less commonly, rash of short duration; hence, patients were treated as outpatients.

CONCLUSION

3F8/GM-CSF is well tolerated and shows promise for treatment of minimal residual NB in BM.

Monoclonal antibody-based therapy of neuroblastoma

The curative potential of mAbs in the treatment of patients with metastatic neuroblastoma is increasingly evident. The idiotype network appears to represent one component of a complex mechanism for success with mAb-based immunotherapy. Ongoing strategies to modify or reconstruct mAbs, to engage them with cytokines, or to unite them with T cells open new avenues for harnessing the unique forces of the immune system against some of the most deadly pediatric cancers.

Topotecan combined with myeloablative doses of thiotepa and carboplatin for neuroblastoma, brain tumors, and other poor-risk solid tumors in children and young adults

Topotecan appears to be relatively unaffected by the most common multidrug resistance mechanisms, may potentiate cytotoxicity of alkylators, has good penetration into the central nervous system, is active against a variety of neoplasms, and has myelosuppression as its paramount toxicity. We present our experience with a myeloablative regimen that includes topotecan. Twenty-one patients with poor-prognosis tumors and intact function of key organs received topotecan 2 mg/m2 by 30-min intravenous (i.v.) infusion on days -8, -7, -6, -5, -4; thiotepa 300 mg/m2 by 3 h i.v. infusion on days -8, -7, -6; and carboplatin by 4 h i.v. infusion on days -5, -4, -3 with a daily dose derived from the pediatric Calvert formula, using a targeted area under the curve of seven mg/ml* min ( approximately 500 mg/m2/day). Stem cell rescue was on day 0. The patients were 1 to 29 (median 4) years old; 18 were in complete remission (CR) and three in partial remission (PR). Early toxicities were severe mucositis and erythema with superficial peeling in all patients and a seizure, hypertension, and renal insufficiency followed by veno-occlusive disease in one patient each. Post-transplant treatment included radiotherapy alone (four patients) or plus biological agents (11 patients with neuroblastoma). With a follow-up of 6+ to 32+ (median 11+) months, event-free survivors include 10/11 neuroblastoma patients (first CR), 4/5 brain tumor patients (second PR or CR), 1/3 patients with metastatic Ewing's sarcoma (first or second CR), and a patient transplanted for multiply recurrent immature ovarian teratoma; a patient with desmoplastic small round-cell tumor (second PR) had progressive disease at 8 months. Favorable results for disease control, manageable toxicity, and the antitumor profiles of topotecan, thiotepa, and carboplatin, support use of this three-drug regimen in the treatment of neuroblastoma and brain tumors; applicability to other tumors is still uncertain.

Extending positron emission tomography scan utility to high-risk neuroblastoma: fluorine-18 fluorodeoxyglucose positron emission tomography as sole imaging modality in follow-up of patients

PURPOSE

Although positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose ((18)F-FDG) has a major impact on the treatment of adult cancer, the reported experience with extracranial tumors of childhood is limited. We describe a role for PET in patients with neuroblastoma (NB).

PATIENTS AND METHODS

In 51 patients with high-risk NB, 92 PET scans were part of a staging evaluation that included iodine-123 or iodine-131 metaiodobenzylguanidine (MIBG) scan, bone scan, computed tomography (and/or magnetic resonance imaging), urine catecholamine measurements, and bone marrow (BM) examinations. The minimum number of tests sufficient to detect NB was determined.

RESULTS

Of 40 patients who were not in complete remission, only 1 (2.5%) had NB that would have been missed had a staging evaluation been limited to PET and BM studies, and 13 (32.5%) had NB detected by PET but not by BM and urine tests. PET was equal or superior to MIBG scans for identifying NB in soft tissue and extracranial skeletal structures, for revealing small lesions, and for delineating the extent and localizing sites of disease. In 36 evaluations of 22 patients with NB in soft tissue, PET failed to identify only two long-standing MIBG-negative abdominal masses. PET and MIBG scans showed more skeletal lesions than bone scans, but the normally high physiologic brain uptake of FDG blocked PET visualization of cranial vault lesions. Similar to MIBG, FDG skeletal uptake was diffusely increased with extensive or progressing BM disease but faint or absent with minimal or nonprogressing BM disease.

CONCLUSION

In the absence or after resolution of cranial vault lesions, and once the primary tumor is resected, PET and BM tests suffice for monitoring NB patients at high risk for progressive disease in soft tissue and bone/BM.

Novel histaprodifen analogues as potent histamine H1-receptor agonists in the pithed and in the anaesthetized rat

We have shown previously that histaprodifen and its Nalpha-substituted analogues methylhistaprodifen and dimethylhistaprodifen are highly potent H1-receptor agonists in vivo. The aim of the present study was to examine the influence of four newly synthesized histaprodifen analogues, 3-fluoro-methylhistaprodifen (1), Nalpha-imidazolylethylhistaprodifen (2), bis-histaprodifen (3) and Nalpha-methyl-bis-histaprodifen (4), on the cardiovascular system in the pithed and in the anaesthetized rat. In pithed and vagotomized rats, diastolic blood pressure (which was increased to 80-85 mmHg by vasopressin infusion) was decreased dose dependently by methylhistaprodifen (the reference compound) and by compounds 1-4. The maximum decrease was about 47-50 mmHg for methylhistaprodifen and compounds 1, 2 and 3. Their potencies, expressed as pED50 (the negative logarithm of the dose in mole per kilogram body weight that decreased diastolic blood pressure by 25 mmHg), were 8.31, 8.23, 8.26 and 7.84, respectively. With compound 4 the maximal effect was not achieved at doses up to 1 micromol/kg (the latter dose decreased blood pressure by about 30 mmHg; pED50 approximately 6.5). The vasodepressor effect of the five compounds was attenuated by the H1-receptor antagonist dimetindene (1 micromol/kg) but was not changed by combined administration of the H2- and H3-receptor antagonists ranitidine and thioperamide (1 micromol/kg each), by combined administration of the alpha1- and alpha2-adrenoceptor antagonists prazosin and rauwolscine (1 micromol/kg each) or by the beta-adrenoceptor antagonist propranolol (3 micromol/kg). In anaesthetized rats methylhistaprodifen and compounds 1-4 induced almost the same fall in blood pressure as in pithed and vagotomized animals; the effects were sensitive to blockade by dimetindene (1 micromol/kg). Higher doses of compounds 1 and 2 (1 micromol/kg) increased heart rate in pithed and vagotomized rats in a manner sensitive to propranolol (3 micromol/kg) but insensitive to dimetindene (3 micromol/kg). The same dose of methylhistaprodifen and of compounds 3 and 4 failed to affect heart rate. We conclude that the agonistic potency of compounds 1 and 2 at H1-receptors in the cardiovascular system of the rat equals that of methylhistaprodifen, the most potent histamine H1-receptor agonist available until recently. Compounds 1 and 2 exhibit sympathomimetic activity at high doses.

Hyperfractionated low-dose radiotherapy for high-risk neuroblastoma after intensive chemotherapy and surgery

PURPOSE

To assess prognostic factors for local control in high-risk neuroblastoma patients treated with hyperfractionated 21-Gy total dose to consolidate remission achieved by dose-intensive chemotherapy and surgery.

PATIENTS AND METHODS

Patients with high-risk neuroblastoma in first remission received local radiotherapy (RT) totaling 21 Gy in twice-daily 1.5-Gy fractions. RT to the primary site followed dose-intensive chemotherapy and tumor resection; the target field encompassed the extent of tumor at diagnosis, plus 3-cm margins and regional lymph nodes. RT to distant sites followed radiologic evidence of response. Local failure was correlated with clinical factors (including other consolidative treatments) and biologic findings.

RESULTS

Of 99 consecutively irradiated patients followed for a median of 21.1 months from RT, 10 relapsed in or at margins of RT fields at 1 to 27 months (median, 14 months). At 36 months after RT, the probability of primary-site failure was 10.1% +/- 5.3%. No primary-site relapses occurred among the 23 patients whose tumors were excised at diagnosis, but there were three such relapses among the seven patients who were irradiated with evidence of residual disease in the primary site. Four of 18 patients with MYCN-amplified disease and serum lactate dehydrogenase greater than 1,500 U/L had local failures (23.4% +/- 10.7% risk at 18 months). Acute radiotoxicities were insignificant, but three of 35 patients followed for > or = 36 months had short stature from decreased growth of irradiated vertebra.

CONCLUSION

Hyperfractionated 21-Gy RT is well tolerated and, together with dose-intensive chemotherapy and surgery, may help in local control of high-risk neuroblastoma. Extending the RT field to definitively encompass regional nodal groups may improve results. Visible residual disease may warrant higher RT dosing. Patients with biologically unfavorable disease may be at increased risk for local failure. RT to the primary site may not be necessary when tumors are excised at diagnosis.

Monoclonal antibody 8H9 targets a novel cell surface antigen expressed by a wide spectrum of human solid tumors

Tumor-restricted surface antigens may be targets for diagnosis and immune-based therapies. Monoclonal antibody 8H9 is a murine IgG1 hybridoma derived from the fusion of mouse myeloma SP2/0 cells and splenic lymphocytes from BALB/c mice immunized with human neuroblastoma. By immunohistochemistry, 8H9 was highly reactive with human brain tumors, childhood sarcomas, and neuroblastomas, and less so with adenocarcinomas. Among primary brain tumors, 15 of 17 glioblastomas, 3 of 4 mixed gliomas, 4 of 11 oligodendrogliomas, 6 of 8 astrocytomas, 2 of 2 meningiomas, 3 of 3 schwannomas, 2 of 2 medulloblastomas, 1 of 1 neurofibroma, 1 of 2 neuronoglial tumors, 2 of 3 ependymomas, and 1 of 1 pineoblastoma tested positive. Among sarcomas, 21 of 21 Ewing's/primitive neuroectodermal tumor, 28 of 29 rhabdomyosarcomas, 28 of 29 osteosarcomas, 35 of 37 desmoplastic small round cell tumors, 2 of 3 synovial sarcomas, 4 of 4 leiomyosarcomas, 1 of 1 malignant fibrous histiocytoma, and 2 of 2 undifferentiated sarcomas tested positive with 8H9. Eighty-seven of 90 neuroblastomas, 12 of 16 melanomas, 3 of 4 hepatoblastomas, 7 of 8 Wilms' tumors, 3 of 3 rhabdoid tumors, and 12 of 27 adenocarcinomas also tested positive. In contrast, 8H9 was nonreactive with normal human tissues including bone marrow, colon, stomach, heart, lung, muscle, thyroid, testes, pancreas, and human brain (frontal lobe, cerebellum, pons, and spinal cord). Reactivity with normal cynomolgus monkey tissue was restricted similarly. Indirect immunofluorescence localized the antigen recognized by 8H9 to the cell membrane. The antigen is proteinase sensitive and is not easily modulated off the cell surface. 8H9 immunoprecipitated a M(r) 58,000 band after N-glycanase treatment, most likely a protein with a heterogeneous degree of glycosylation. This novel antibody-antigen system may have potential for tumor targeting.

Frederine, a new and promising protector against doxorubicin-induced cardiotoxicity

The flavonoid 7-monohydroxyethylrutoside (monoHER) can protect against doxorubicin-induced cardiotoxicity. A drawback of monoHER therapy would be the relatively high dose needed to obtain complete protection (500 mg/kg in mice). Therefore, we synthesized a series of new compounds with improved antioxidant properties. After characterization of antioxidant activity, cardioprotection in vitro, and possible toxic properties in hepatocytes, we selected Frederine for additional investigations in vivo. In the present study, it was found that this compound did not induce weight loss or (gross) organ changes in mice in a treatment schedule of 170 mg/kg i.p., 5 times/week during 2 weeks. We recorded the electrocardiogram telemetrically in mice during and 2 weeks after the combined treatment with doxorubicin (4 mg/kg, i.v.) and 5 times Frederine (68 mg/kg, i.p.; equimolar to 100 mg/kg monoHER) for 6 weeks. Complete protection against doxorubicin-induced cardiotoxicity was found, indicating that Frederine is at least 5 times more potent than monoHER. Frederine did not have a negative influence on the antiproliferative effects of doxorubicin on A2780, OVCAR-3, and MCF-7 cells in vitro and on OVCAR-3 xenografts grown in nude mice when administered 5 min before doxorubicin (8 mg/kg i.v.) and 4 days thereafter with an interval of 24 h. It can be concluded that we succeeded in designing a better cardioprotector than monoHER. Therefore, Frederine merits further investigation as a possible protector against doxorubicin-induced cardiotoxicity in cancer patients.

Neuroblastoma metastatic to the central nervous system. The Memorial Sloan-kettering Cancer Center Experience and A Literature Review

BACKGROUND

The central nervous system (CNS) can be a sanctuary site for cancer cells, because the blood-brain barrier impedes penetration of most chemotherapeutic agents. The authors hypothesized that, with improved survival from childhood metastatic neuroblastoma (NB), the incidence of CNS (intraparenchymal and leptomeningeal) spread may increase. They undertook this study to assess the frequency of CNS NB, to analyze risk factors and treatment options, and to review the literature.

METHODS

The authors retrospectively analyzed all patients with metastatic NB who were treated on protocols N4, N5, N6, and N7 from 1980 to 1999 at Memorial Sloan-Kettering Cancer Center (MSKCC), during which time there was an increase in the overall survival rate.

RESULTS

Two hundred fifty-one patients with Stage 4 NB (Group 251) were studied, of which 127 (Group 127) were newly diagnosed patients who were treated initially at MSKCC. None had CNS NB at the time of diagnosis. Eleven patients developed documented CNS disease; 8 of these 11 recurrences were isolated in the CNS. For Group 127, the overall incidence rate of CNS NB was 6.3%, with an increase in incidence from N4-N5 to N6-N7 of from 1.7% to 11.7%. Seven patients had isolated CNS disease recurrences. Only lumbar punctures (LP) performed near the time of diagnosis in patients with known bone marrow involvement were associated with subsequent development of CNS disease. For the entire group of 251 patients, lumbar puncture at the time of diagnosis and elevated serum lactic dehydrogenase levels were prognostic. Among the larger series reported in the literature, CNS involvement from metastatic lesions was rare at the time of diagnosis and remained an uncommon complication.

CONCLUSIONS

The incidence of CNS NB may be increasing. Because it is the sole site of disease recurrence in 64% of patients, the CNS may represent a sanctuary site for NB. CNS NB is associated with diagnostic lumbar punctures in patients with known bone marrow disease, raising the possibility that circulating or epidural microscopic tumor cells may seed the craniospinal axis.

The use of radiotelemetry in small laboratory animals: recent advances

Radiotelemetry provides an alternative means of obtaining physiological measurements from awake and freely moving laboratory animals, without introducing stress artifacts. For researchers, especially those in the fields of pharmacology and toxicology, the technique may provide a valuable tool for predicting the effectiveness and safety of new compounds in humans. In light of studies described in the literature, it is concluded that there is ample evidence that the use of radiotelemetry for measuring blood pressure, cardiac activity, heart rate, body temperature, and locomotor activity in rodents has been validated sufficiently. Today, this technology is an important tool for the stress-free collection of these physiologic data in small rodents, including mice.

Principal component analysis of mass spectra of peptides generated from the tryptic digestion of protein mixtures

Principal component analysis (PCA) has been used to analyse mass spectral peptide profiles obtained from the enzymatic digestion of standard protein mixtures. Scores and loadings plots clearly revealed peptide fragments that differentiated one protein mixture from another. Peptide map search results identified with a high degree of certainty any additional proteins in these mixtures. As a proof-of-concept this methodology was applied to hepatic protein mixtures obtained from rats treated with two hepatotoxic compounds: methapyriline and SB-219994. Liver proteins were extracted, pre-separated by one-dimensional polyacrylamide gel electrophoresis, subjected to tryptic digestion and analysed by mass spectrometry. Two up-regulated proteins, glutathione S-transferase with methapyrilene and peroxisomal bifunctional enzyme with SB-219994, were identified in this manner.

Long-term monitoring of atrazine contamination in soil by ELISA

An enzyme-linked immunoassay (ELISA) was used for screening atrazine residues in soil. Samples were annually collected in Southern Germany between 1993 and 1998. An average of 419.5 samples was analyzed per year amounting to 2517 samples. The fraction of positive samples defined by atrazine concentrations >100 microg/kg soil decreased successively from 8% (corresponding to 33 samples) in 1993 to 0.6% (corresponding to 2 samples) in 1998. All positive samples and a selection of negative samples were subsequently validated by HPLC. Comparison of ELISA and HPLC data yielded correlation coefficient values of r = 0.958-0.981 (n = 18-47), except for 1995 when only a correlation of r = 0.864 (n = 18) was obtained. Four samples were overestimated and another 4 were underestimated with respect to the atrazine threshold value of 100 microg/kg soil as revealed by HPLC validation. Thus, 99.68% of 2,517 analyzed samples were correctly evaluated. The precision and reproducibility of the ELISA were adequate for a prescreening tool. The low cost per sample and the high sample throughput are not yet achievable by conventional analytical methods. The described combination of ELISA and HPLC has the potential to take advantage of both methods and to restrict determination errors to a minimum.

N7: a novel multi-modality therapy of high risk neuroblastoma (NB) in children diagnosed over 1 year of age

BACKGROUND

The N7 protocol for poor-risk neuroblastoma uses dose-intensive chemotherapy (as in N6 protocol [Kushner et al.: J Clin Oncol 12:2607-2613, 1994] but with lower dosing of vincristine) for induction, surgical resection and 2100 cGy hyperfractionated radiotherapy for local control, and for consolidation, targeted radioimmunotherapy with 131I-labeled anti-GD2 3F8 monoclonal antibody and immunotherapy with unlabeled/unmodified 3F8 (400 mg/m2).

PROCEDURE

The chemotherapy consists of: cyclophosphamide 70 mg/kg/d x 2 and a 72-hr infusion of doxorubicin 75 mg/m2 plus vincristine 2 mg/m2, for courses 1, 2, 4, and 6; and cisplatin 50 mg/m2/d x 4 and etoposide 200 mg/m2/d x 3, for courses 3, 5, and 7. 131I-3F8 is dosed at 20 mCi/kg, which is myeloablative and therefore necessitates stem-cell support.

RESULTS

Of the first 24 consecutive previously untreated patients more than 1 year old at diagnosis, 22 were stage 4 and two were unresectable stage 3 with MYCN amplification. Chemotherapy achieved CR/VGPR in 21 of 24 patients. Twenty patients to date have completed treatment with 131I-3F8, and 15 patients have completed all treatment. With a median follow-up of 19 months, 18 of 24 patients remain progression-free.

CONCLUSIONS

Major toxicities were grade 4 myelosuppression and mucositis during chemotherapy, and self-limited pain and urticaria during antibody treatment. Late effects include hearing deficits and hypothyroidism.