Disaloganglioside GD2 loss following monoclonal antibody therapy is rare in neuroblastoma

BACKGROUND

Gangliosicle GD2 is abundant on human neuroblastoma (NB). Monoclonal antibody 3F8 targeted to GD2 may have imaging and therapeutic potential. Antigen-negative clones can escape immune-mediated attack leading to clinical resistance or recurrence.

PROCEDURE

Among 95 evaluable patients treated intravenously with 3F8 (94 Stage 4, 1 Stage 3), 66 received nonradiolabeled 3F8, 11 received 131-iodine-labeled-3F8 (8-28 mCi/kg) with autologous bone marrow rescue, and 18 received both forms of treatment. Prior to treatment, 90 patients tested positive for GD2 reactivity by bone marrow immunofluorescence (n = 68), tumor immunohistochemistry (n = 20), or diagnostic radioimmunoscintigraphy (n = 2).

RESULTS

Of 62 patients who had refractory or recurrent neuroblastoma following 3F8 treatment, 61 (98%) tested positive for GD2 reactivity by bone marrow immunofluorescence (n = 51) or tumor immunohistochemistry (n = 10). The sole tumor that lost GD2 expression underwent phenotypic transformation into a pheochromocytoma-like tumor.

CONCLUSIONS

The persistence of GD2 expression in refractory or recurrent NB suggests that complete antigen loss is an uncommon event and cannot account for treatment failure.

Strange magnetism and the anapole structure of the proton

The violation of mirror symmetry in the weak force provides a powerful tool to study the internal structure of the proton. Experimental results have been obtained that address the role of strange quarks in generating nuclear magnetism. The measurement reported here provides an unambiguous constraint on strange quark contributions to the proton's magnetic moment through the electron-proton weak interaction. We also report evidence for the existence of a parity-violating electromagnetic effect known as the anapole moment of the proton. The proton's anapole moment is not yet well understood theoretically, but it could have important implications for precision weak interaction studies in atomic systems such as cesium.

Targeted radioimmunotherapy for leptomeningeal cancer using (131)I-3F8

BACKGROUND

Intrathecal antibody-based targeted therapies may have clinical potential for patients with leptomeningeal (LM) cancer.

PROCEDURE

Five patients with GD2-positive LM tumors were injected with 1-2 mCi intra-Ommaya (131)I-3F8, a murine IgG3 antibody specific for GD2. Serial cerebrospinal fluid (CSF) and serum samples and SPECT imagings (4, 24, and 48 hr) were performed to predict radiation doses to the tumor and normal brain and blood prior to the administration of larger therapeutic doses.

RESULTS

Side effects included self-limited fever, headache, and vomiting. Focal (131)I-3F8 uptake consistent with tumors was seen along the craniospinal axis in four patients. Calculated radiation dose to the CSF was 14.9-56 cGy/mCi and to blood and other organs outside the CNS less than 2 cGy/mCi.

CONCLUSIONS

Intraventricular (131)I-3F8 successfully detected LM disease and resulted in a large favorable CSF/blood ratio. Intraventricular (131)I-3F8 may have clinical utility in the diagnosis and radioimmunotherapy of GD2-positive LM cancers. Med. Pediatr. Oncol. 35:716-718. 2000.

Granulocyte-colony stimulating factor and multiple cycles of strongly myelosuppressive alkylator-based combination chemotherapy in children with neuroblastoma

BACKGROUND

The authors assessed key effects of granulocyte-colony stimulating factor (G-CSF) used prophylactically with multiple cycles of strongly myelosuppressive alkylator-based combination chemotherapy. To the authors' knowledge, no large study has focused on G-CSF in this setting, yet this kind of treatment has recently become standard for poor risk pediatric solid tumors such as neuroblastoma. PATIENTS AND METHODS. Children with neuroblastoma received cyclophosphamide 140 mg/kg (i.e., 4200 mg/m(2)), doxorubicin 75 mg/m(2), and vincristine (CAV) in cycles 1, 2, 4, and 6 and cisplatin 200 mg/m(2) and etoposide 600 mg/m(2) (P/VP) in cycles 3, 5, and 7. To maximize dose intensity, chemotherapy was begun as soon as the absolute neutrophil count (ANC) was > or = 500/microL and platelet count was > or = 100,000/microL. No cytokines were used during 1990-1994 (control group; n = 28), but G-CSF was used from 1995 to 1998 (G-CSF group; n = 30) at 5 microg/kg/day subcutaneously from 1 day after chemotherapy until the ANC was > or = 500/microL on 2 successive days or was > or = 1000/microL.

RESULTS

Each cycle of CAV decreased ANCs to < 200/microL in all 58 patients; recovery to 200/microL and to 500/microL was significantly sooner with G-CSF. In contrast, P/VP did not invariably cause severe neutropenia: similar numbers of patients in each group maintained ANCs > or = 200/microL and > or = 500/microL; recovery to 500/microL (but not to 200/microL) was significantly faster in the G-CSF group. G-CSF had no impact on rates of febrile episodes. Bacterial/fungal infections were slightly less frequent in the G-CSF group with CAV (P = 0.11) but not with P/VP. Dose intensity through cycle 4 was the same in both groups. Beginning with cycle 3, G-CSF patients had slower recovery to platelet counts > or = 100,000/microL. Response rates were similar in the two groups.

CONCLUSIONS

With multiple cycles of strongly myelosuppressive alkylator-based combination chemotherapy, prophylactic use of G-CSF hastened ANC recovery but did not reduce the incidence of febrile episodes, had little impact on infection rates, did not yield augmented dose intensity, was associated with prolonged thrombocytopenia, and had no effect on response rates of neuroblastoma. The data support more limited use of G-CSF.

Pilot study of topotecan and high-dose cyclophosphamide for resistant pediatric solid tumors

BACKGROUND

The recommended dosages of topotecan and cyclophosphamide in combination for prior-treated patients-3.75 mg/m(2) and 1,250 mg/m(2) in children, 5 mg/m(2) and 600 mg/m(2) in adults, respectively-are well below those of each agent when used singly. We tested the hypothesis that much higher dosing would meet critical goals of salvage therapy: antitumor effect and a lack of toxicity to key organs, so as not to preclude subsequent consolidative treatments needed for cure.

PROCEDURE

Patients with resistant pediatric solid tumors received cyclophosphamide 4,200 mg/m(2) by 48 hr infusion, and topotecan 6 mg/m(2) by 72 hr infusion (HD-Cy/Topo). Mesna and granulocyte colony-stimulating factor were used. Cycles were repeated when neutrophil counts were >1,000/uL and platelet counts were >75,000/uL.

RESULTS

Twenty-eight patients, aged 2 to 33 years (median, 14), received one (n = 4), two (n = 15), or > or =3 (n = 9) cycles of HD-Cy/Topo. All patients had previously received > or =6 cycles of other therapy, high-dose alkylator-based chemotherapy, and/or etoposide- and doxorubicin-containing regimens. HD-Cy/Topo was given in an outpatient setting. Profound myelosuppression was the major toxicity, but retreatment was possible by day 28, and preliminary results with peripheral blood stem cell collections showed a sparing effect on hemopoietic stem cells. Mucositis was uncommon. After HD-Cy/Topo, cardiac, renal, hepatic, and pulmonary function remained within the normal range. Partial or minor responses were noted in neuroblastoma, desmoplastic small round-cell tumor, Ewing sarcoma, rhabdomyosarcoma, and osteosarcoma.

CONCLUSIONS

Its antitumor potential and limited toxicity make HD-Cy/Topo an attractive choice for inclusion in aggressive salvage programs aimed at achieving cures of resistant tumors. It may also merit incorporation into frontline treatment protocols.

Sweet's syndrome in association with Crohn's disease

A case of Sweet's syndrome in association with Crohn's disease in a young woman is reported. Sweet's syndrome is a rare extraintestinal manifestation of Crohn's disease and ulcerative colitis.

Transverse asymmetry AT' from the quasielastic 3He(e,e') process and the neutron magnetic form factor

We have measured the transverse asymmetry A(T') in 3He(e,e(')) quasielastic scattering in Hall A at Jefferson Laboratory with high precision for Q2 values from 0.1 to 0.6 (GeV/c)(2). The neutron magnetic form factor G(n)(M) was extracted based on Faddeev calculations for Q2 = 0.1 and 0.2 (GeV/c)(2) with an experimental uncertainty of less than 2%.

Flash pulmonary edema: association with hypertension and reoccurrence despite coronary revascularization

BACKGROUND

The sudden development of acute (flash) pulmonary edema may be an indication for coronary angiography and revascularization. However, the prevalence of coronary artery disease in these patients and the outcome after revascularization are not known.

METHODS AND RESULTS

We evaluated 46 patients with an initial presentation of flash pulmonary edema requiring hospitalization and obtained up to 3 years of follow-up in 45 patients. There were 22 men and 24 women, 44 to 84 years of age (67 +/- 10 years, mean +/- SD). Systolic blood pressure on admission was 194 +/- 38 mm Hg. Twenty-four patients required intubation and mechanical ventilation. Left ventricular ejection fraction was >40% in 27 of 46 patients. Thirty-eight patients underwent coronary angiography; 33 had obstructive coronary artery disease. One other patient had regional wall motion abnormalities. Nineteen patients underwent coronary revascularization surgically and 8 percutaneously. Overall, flash pulmonary edema reoccurred in one half of the patients. Of the 19 patients who underwent coronary revascularization, by 6 months there was 1 death and 9 patients had been hospitalized with recurrent pulmonary edema.

CONCLUSIONS

Many patients with flash pulmonary edema have preserved systolic left ventricular function and coronary artery disease. Flash pulmonary edema frequently reoccurs in association with marked systolic hypertension, even after coronary revascularization. This suggests that control of hypertension is important and that coronary revascularization may not be adequate to prevent reoccurrence of flash pulmonary edema.

The importance of phenology for the evaluation of impact of climate change on growth of boreal, temperate and Mediterranean forests ecosystems: an overview

An overview is presented of the phenological models relevant for boreal coniferous, temperate-zone deciduous and Mediterranean coniferous forest ecosystems. The phenology of the boreal forests is mainly driven by temperature, affecting the timing of the start of the growing season and thereby its duration, and the level of frost hardiness and thereby the reduction of foliage area and photosynthetic capacity by severe frost events. The phenology of temperate-zone forests is also mainly driven by temperature. Since temperate-zone forests are mostly mixed-species deciduous forests, differences in phenological response may affect competition between tree species. The phenology of Mediterranean coniferous forests is mainly driven by water availability, affecting the development of leaf area, rather than the timing of phenological events. These phenological models were subsequently coupled to the process-based forest model FORGRO to evaluate the effect of different climate change scenarios on growth. The results indicate that the phenology of each of the forest types significantly affects the growth response to a given climate change scenario. The absolute responses presented in this study should, however, be used with caution as there are still uncertainties in the phenological models, the growth models, the parameter values obtained and the climate change scenarios used. Future research should attempt to reduce these uncertainties. It is recommended that phenological models that describe the mechanisms by which seasonality in climatic drivers affects the phenological aspects of trees should be developed and carefully tested. Only by using such models may we make an assessment of the impact of climate change on the functioning and productivity of different forest ecosystems.

Virulent rough filaments of Listeria monocytogenes from clinical and food samples secreting wild-type levels of cell-free p60 protein

Atypical rough cell filaments of Listeria monocytogenes (designated FR variants), isolated from clinical and food samples, form long filaments up to 96 microm in length and demonstrated wild-type levels of adherence, invasion, and cytotoxicity to human epithelial HEp-2, Caco-2, and HeLa cells. Unlike previously described avirulent rough mutants of L. monocytogenes that secrete diminished levels of the major extracellular protein p60 and that form long chains that consist of multiple cells of similar size (designated MCR variants), FR variants secreted wild-type or greater levels of p60. This study shows that virulent filamentous forms of L. monocytogenes occur in clinical and food environments and have atypical morphological characteristics compared to those of the wild-type form.

Telemetric monitoring of blood pressure in freely moving mice: a preliminary study

This paper describes for the first time the possibility for recording the systolic pressure (SP), diastolic pressure (DP), and the mean arterial pressure (MAP) as well as the heart rate (HR) and locomotor activity (LA) in freely moving mice, using a commercially available telemetry and data acquisition system. The system comprises a new, small radio-telemetry transmitter implanted in the peritoneal cavity, a receiver board placed underneath the home cage, a multiplexer and a computer-based data acquisition system. The signals from the receiver were consolidated by the multiplexer and were stored and analysed by the computer. The telemetered pressure signals (absolute pressure) were corrected automatically for changes in atmospheric pressure measured by an ambient pressure monitor. The effects of implantation on animal behaviour, and, after the animals had recovered, the effects of handling on the SP, DP, MAP and HR were examined. The radio-telemetry system for recording the SP, DP, MAP and HR provides an accurate and reliable method for monitoring the direct effects of handling on SP, DP, MAP and HR. In addition, by using this new blood pressure (BP) transmitter, we maintain that BP measurements in freely moving mice are more efficient, reliable, and less labour-intensive than the measurement techniques described in the literature thus far.

[Juxta-articular fibroid nodules and acrodermatitis chronica atrophicans in late stage Lyme borreliosis]

A 60-years old female patient developed juxta-articular fibroid nodules and erythrocyanotic lesions of acrodermatitis chronica atrophicans after several tick bites. The woman was treated with ceftriaxon (Rocephin) 2 g daily parenterally without adverse reactions.

A new method for measurement of blood pressure, heart rate, and activity in the mouse by radiotelemetry

A simple and reliable means for accurate, chronic measurement of pulsatile blood pressure (BP) from conscious, freely moving laboratory mice was developed and validated. The newly developed device consists of a small (1.9 ml, 3.4 g), fully implantable radiotelemetry transmitter. Initial frequency response tests showed an adequate dynamic response; the average -3-dB point found in five transmitters was 145 +/- 14 (SD) Hz. BP, heart rate, and locomotor activity were recorded from 16 chronically (30-150 days) implanted mice. Mean arterial and pulse pressure, checked at regular intervals, ranged from 90-140 mmHg and from 30-50 mmHg, respectively, throughout the study. Transmitter BP measurements were validated against a Millar 1.4-Fr. transducer-tipped catheter. The mean error of the transmitters for diastolic pressures was +1.1 +/- 6.9 mmHg (n = 7). The error for systolic pressures was, on average, 2.7 +/- 3.9 mmHg larger. This new device accurately monitors BP, heart rate, and locomotor activity in conscious, untethered, freely moving mice living in their home cages for periods of at least 150 days.

7-monohydroxyethylrutoside protects against chronic doxorubicin-induced cardiotoxicity when administered only once per week

Doxorubicin is a very effective antitumor agent, but its clinical use is limited by the occurrence of a cumulative dose-related cardiotoxicity, resulting in congestive heart failure. 7-Monohydroxyethylrutoside (monoHER), a flavonoid belonging to the semisynthetic hydroxyethylrutoside family, has been shown to protect against doxorubicin-induced cardiotoxicity when administered i.p. at a dose of 500 mg/kg five times/week in combination with a weekly i.v. dose of doxorubicin. Such a dosing schedule would be very inconvenient in clinical practice. We therefore investigated a dosing schedule of one administration of monoHER just before doxorubicin. The electrocardiogram was measured telemetrically in mice after the combined treatment of doxorubicin (4 mg/kg, i.v.) with one dose of monoHER (500 mg/kg, i.p., administered 1 h before doxorubicin) for 6 weeks. These data were compared with the five times/week schedule (500 mg/kg, i.p., administered 1 h before doxorubicin and every 24 h for 4 days). The increase of the ST interval was used as a measure for cardiotoxicity. It was shown that 500 mg/kg monoHER administered only 1 h before doxorubicin provided complete protection against the cardiotoxicity. This protection was present for at least 10 weeks after the last treatment. Because of the short half-life of monoHER, these results suggest that the presence of monoHER is only necessary during the highest plasma levels of doxorubicin.

Histaprodifens: synthesis, pharmacological in vitro evaluation, and molecular modeling of a new class of highly active and selective histamine H(1)-receptor agonists

A new class of histamine analogues characterized by a 3, 3-diphenylpropyl substituent at the 2-position of the imidazole nucleus has been prepared outgoing from 4,4-diphenylbutyronitrile (4b) via cyclization of the corresponding methyl imidate 5b with 2-oxo-4-phthalimido-1-butyl acetate or 2-oxo-1,4-butandiol in liquid ammonia, followed by standard reactions. The title compounds displayed partial agonism on contractile H(1) receptors of the guinea-pig ileum and endothelium-denuded aorta, respectively, except 10 (histaprodifen; 2-[2-(3, 3-diphenylpropyl)-1H-imidazol-4-yl]ethanamine) which was a full agonist in the ileum assay. While 10 was equipotent with histamine (1), methylhistaprodifen (13) and dimethylhistaprodifen (14) exceeded the functional potency of 1 by a factor of 3-5 (13) and 2-3 (14). Compounds 10 and 13-17 relaxed precontracted rat aortic rings (intact endothelium) with relative potencies of 3.3- up to 28-fold (compared with 1), displaying partial agonism as well. Agonist effects were sensitive to blockade by the selective H(1)-receptor antagonist mepyramine (pA(2) approximately 9 (guinea-pig) and pA(2) approximately 8 (rat aorta)). The affinity of 10 and 13-17 for guinea-pig H(1) receptors increased 20- to 100-fold compared with 1. Two lower homologues of 10 were weak partial H(1)-receptor agonists while two higher homologues of 10 were silent antagonists endowed with micromolar affinity for rat and guinea-pig H(1) receptors. In functional selectivity experiments, 10, 13, and 14 did not stimulate H(2), H(3), and several other neurotransmitter receptors. They displayed only low to moderate affinity for these sites (pA(2) < 6). For a better understanding of structure-activity relationships, the interaction of 1 and 10, 13 and 14 within the transmembrane (TM) domains of the human histamine H(1) receptor were studied using molecular dynamics simulations. Remarkable differences were found between the binding modes of 10, 13, and 14 and that of 1. The imidazole ring of 10, 13, and 14 was placed 'upside down' compared with 1, making the interaction of the N(pi)-atom with Tyr431 possible. This new orientation was mainly caused by the space filling substitution at the 2-position of the imidazole ring and influenced the location of the protonated N(alpha)-atom which was positioned more between TM III and TM VI. This orientation can explain both the increased relative potency and the maximum effect of 10, 13, and 14 compared with 1. Compound 13 (methylhistaprodifen; N(alpha)-methyl-2-[2-(3, 3-diphenylpropyl)-1H-imidazol-4-yl]ethanamine) is the most potent histamine H(1)-receptor agonist reported so far in the literature and may become a valuable tool for the study of physiological and pathophysiological H(1)-receptor-mediated effects.

Local control with multimodality therapy for stage 4 neuroblastoma

PURPOSE

To evaluate the efficacy of 21 Gy hyperfractionated radiotherapy for local control in conjunction with surgery and intensive systemic therapy for patients with Stage 4 neuroblastoma.

METHODS AND MATERIALS

After achieving a partial or complete remission, 47 children, ages 1-10 years, with Stage 4 neuroblastoma were treated on four consecutive institutional protocols (N4-N7) with dose-intensive multi-agent chemotherapy, maximal surgical debulking, and hyperfractionated radiotherapy (1.5 Gy twice a day to 21 Gy). Radiotherapy fields encompassed the initial tumor volume and regional lymph nodes plus a 3-cm margin. This was followed by consolidation with either autologous bone marrow transplantation (N4 and N5) or immunotherapy (N6 and N7).

RESULTS

Forty-five of 47 patients had a complete response to surgery and chemotherapy prior to radiotherapy. Five-year actuarial rates of local control, progression-free survival, and overall survival were 84%, 40%, and 45%, respectively. Among 26 patients who relapsed, 1 failed only at the primary site, 22 developed distant metastases exclusively, and 3 had both local and distant failures. There were no acute complications of radiotherapy.

CONCLUSION

Hyperfractionated radiotherapy to 21 Gy, in conjunction with dose-intensive systemic therapy and aggressive surgical resection, is well tolerated and is associated with durable local control for most patients with Stage 4 neuroblastoma.

Clinical categories of neuroblastoma are associated with different patterns of loss of heterozygosity on chromosome arm 1p

Deletion of the short arm of chromosome 1 is frequently observed in neuroblastoma (NB). We performed loss of heterozygosity (LOH) analysis of 120 well characterized NB to better define specific regions of 1p loss and any association with clinical and biological prognostic features (DNA index, MYCN, age, and stage). All categories of disease were represented including 7 ganglioneuromas, 8 stage 4S, 33 local-regional (stages 1, 2, and 3), and 72 stage 4 NB according to the International Neuroblastoma Staging System. Patients were consistently treated with stage-appropriate protocols at a single institution. Sixteen highly informative, polymorphic loci mapping to chromosome 1 were evaluated using a sensitive, semi-automated, fluorescent detection system. Chromosome arm 1p deletions were detected in all categories of tumor except ganglioneuroma. Frequent LOH was detected at two separate regions of 1p and distinct patterns of losses were associated with individual clinical/biological categories. Clinically aggressive stage 4 tumors were predominantly diploid with extensive LOH frequently detected in the region of 1ptel to 1p35 (55%) and at 1p22 (56%). The shortest region of overlap for LOH at 1p36 was between D1S548 and D1S1592 and for 1p22 was between D1S1618 and D1S2766. Local-regional tumors were mostly hyperdiploid with short regions of loss primarily involving terminal regions of 1p36 (42%). Most spontaneously regressing stage 4S tumors (7/8) were hyperdiploid without loss of 1p36 or 1p22. These findings suggest that genes located on at least two separate regions of chromosome arm 1p play a significant role in the biology of NB and that distinct patterns of 1p LOH occur in individual clinical/biological categories.

Modeling daily gas exchange of a Douglas-fir forest: comparison of three stomatal conductance models with and without a soil water stress function

Modeling stomatal conductance is a key element in predicting tree growth and water use at the stand scale. We compared three commonly used models of stomatal conductance, the Jarvis-Loustau, Ball-Berry and Leuning models, for their suitability for incorporating soil water stress into their formulation, and for their performance in modeling forest ecosystem fluxes. We optimized the parameters of each of the three models with sap flow and soil water content data. The optimized Ball-Berry model showed clear relationships with air temperature and soil water content, whereas the optimized Leuning and Jarvis-Loustau models only showed a relationship with soil water content. We conclude that use of relative humidity instead of vapor pressure deficit, as in the Ball-Berry model, is not suitable for modeling daily gas exchange in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in the Speulderbos forest near the village of Garderen, The Netherlands. Based on the calculated responses to soil water content, we linked a model of forest growth, FORGRO, with a model of soil water, SWIF, to obtain a forest water-balance model that satisfactorily simulated carbon and water (transpiration) fluxes and soil water contents in the Douglas-fir forest for 1995.

Ring-substituted histaprodifen analogues as partial agonists for histamine H(1) receptors: synthesis and structure-activity relationships

Thirteen racemic benzene ring-substituted analogues of histaprodifen (8a; 2-[2-(3,3-diphenylpropyl)-1H-imidazol-4-yl]ethanamine), a novel lead for potent and selective histamine H(1)-receptor agonists, have been prepared from substituted 4,4-diphenylbutyronitriles 5 via cyclization of the corresponding methyl butyrimidates 6 with 2-oxo-4-phthalimido-1-butyl acetate in liquid ammonia, followed by deprotection. Nitriles 5 were accessible by alkylation of either substituted diphenylmethanes with 3-bromopropionitrile or diethyl malonate with substituted 1-chloro-diphenylmethanes and subsequent standard reactions. The title compounds 8 displayed partial agonism on contractile H(1) receptors of the guinea-pig ileum (E(max) = 2-98% relative to histamine) and, compared with the endogenous agonist, were endowed with agonist potencies of 4-92%. The meta fluorinated (8c) and meta chlorinated (8f) analogues showed the highest relative potency in this series (95% confidence limits 85-99% and 78-102%), but did not exceed the value of the lead 8a (99-124%). Compound 8c (2-[2-[3-(3-fluorophenyl)-3-phenylpropyl]-1H-imidazol-4-yl]ethanamine ) was a partial agonist at contractile H(1) receptors of the guinea-pig aorta (relative potency 154% vs. 100% for histamine) and at relaxation-mediating endothelial H(1) receptors of the rat aorta (relative potency 556% vs. 100% for histamine) and matched with the functional behaviour of 8a. Agonism observed for each compound was sensitive to blockade by the selective H(1)-receptor antagonist mepyramine (pA(2) approximately 9 (guinea-pig) and pA(2) approximately 8 (rat aorta)). All histaprodifen analogues 8 stimulated neither histaminergic H(2)/H(3) nor cholinergic M(3) receptors. They displayed only low to moderate affinity for these sites (H(2): pD'(2) < 5; H(3)/M(3): pA(2) < 6). With regard to the substitution pattern on the benzene ring, there was no correlation between the histaprodifen series and the corresponding derivatives of another selective H(1)-receptor agonist, viz. 2-phenylhistamine.

Clinically critical impact of molecular genetic studies in pediatric solid tumors

BACKGROUND

Standard cytogenetic techniques are time-consuming and often not informative with solid tumors. In contrast, the reverse transcriptase-polymerase chain reaction (RT-PCR) is a readily available technique that can rapidly detect tumor-specific chromosomal rearrangements, even in small biopsy specimens. We present cases depicting the importance of including molecular diagnostic studies in the routine evaluation of pediatric solid tumors.

PROCEDURE

We used RT-PCR to detect chimeric transcripts specific for major pediatric solid tumors, including peripheral primitive neuroectodermal tumor (pPNET), alveolar rhabdomyosarcoma (ARMS), and desmoplastic small round-cell tumor (DSRCT). We reviewed six recent cases in which the initial diagnosis was changed by the results of RT-PCR.

RESULTS

Highly unusual or nonspecific clinical and/or histopathologic findings led to the initial diagnoses of neuroblastoma in three patients and DSRCT, leukemia, and carcinoma in one patient each. The final diagnoses after RT-PCR studies were pPNET in three patients, ARMS in two patients, and DSRCT in one patient. RT-PCR results led to early corrections in the diagnosis in two patients, but four patients received treatment not considered optimal for the neoplasms ultimately diagnosed, including three who, despite presenting with localized tumors that have a >70% cure rate with standard therapy, have died or are dying of disease.

CONCLUSIONS

Molecular genetic studies on solid tumors can clarify the diagnosis in seemingly straightforward as well as in overtly problematic cases. These diagnostic distinctions are now critical as disease-specific and risk-directed therapies have emerged.

Oral etoposide for refractory and relapsed neuroblastoma

PURPOSE

To describe the efficacy of oral etoposide against resistant stage 4 neuroblastoma.

PATIENTS AND METHODS

Patients with refractory or recurrent stage 4 neuroblastoma were treated with etoposide 50 mg/m(2) taken orally each day, in two or three divided doses, for 21 consecutive days. Treatment could be repeated after a 1-week period. Extent-of-disease studies included imaging with 131-iodine-metaiodobenzylguanidine and extensive bone marrow (BM) sampling.

RESULTS

Oral etoposide was used in 20 children between the ages of 2 and 11 years (median, 6 years). Prior treatment included high doses of alkylating agents and a median of 4.5 cycles of etoposide-containing chemotherapy, with cumulative etoposide doses of 1,800 mg/m(2) to 3,935 mg/m(2) (median, 2,300 mg/m(2)). Oral etoposide produced antineuroblastoma effects in four of four children with disease refractory to intensive induction treatment; sampling variability could account for resolution (n = 3) or reduction (n = 1) of BM involvement, but improvement in other markers also occurred. Antineuroblastoma effects were also evident in five of five children with asymptomatic relapses after a long chemotherapy-free interval: BM disease resolved and all other disease markers significantly improved in two patients, and disease markers improved or stabilized in three patients on treatment for more than 6 months. In these nine patients, extramedullary toxicity was absent, neutropenia did not occur, transfusional support was not needed, and preliminary data suggested little immunosuppression (phytohemagglutinin responses). Oral etoposide was ineffective in all (11 of 11) patients with rapidly growing tumor masses.

CONCLUSION

Given the absence of toxicity to major organs, the minimal myelosuppression or immunosuppression, and the antineoplastic activity in patients with low tumor burdens after high-dose chemotherapy, limited use of low-dose oral etoposide should be considered for inclusion in postinduction consolidative treatment programs aimed at eradicating minimal residual disease.

A new double-stranded RNA mycovirus from Botrytis cinerea

A simple double-stranded RNA mycovirus was detected in a wild-type Botrytis cinerea 55k strain. The virus was located in the fungus cytoplasm as free particles of approximately 28 nm in diameter. The mycovirus possesses a single double-stranded genome segment of 1.8 kilobase pairs (kbp) encapsidated within an isometric protein coat whose main structural component is a polypeptide of 68 kDa. Cells infected with this virus showed an important degree of cellular degeneration.

Intrauterine fetal diagnosis for hematologic and other congenital disorders

Advances in prenatal diagnostic techniques allow for earlier, more rapid, and more effective detection of congenital disorders. The indications, diagnostic accuracy, and risks for invasive diagnostic techniques including amniocentesis, chorionic villus sampling, and fetal blood sampling are reviewed. Recent advances in non-invasive detection methods, such as fetal ultrasound and the isolation of fetal cells in the maternal circulation are discussed. Additionally, the intrauterine diagnosis of congenital infections and chromosomal and Mendelian disorders, as well as hematologic disorders are summarized.