A Pragmatic Study Evaluating NEPA Versus Aprepitant for Prevention of Chemotherapy-Induced Nausea and Vomiting in Patients Receiving Moderately Emetogenic Chemotherapy

BACKGROUND

Neurokinin (NK) 1 receptor antagonists (RAs), administered in combination with a 5-hydroxytryptamine-3 (5-HT₃ ) RA and dexamethasone (DEX), have demonstrated clear improvements in chemotherapy-induced nausea and vomiting (CINV) prevention over a 5-HT₃ RA plus DEX. However, studies comparing the NK₁ RAs in the class are lacking. A fixed combination of a highly selective NK₁ RA, netupitant, and the 5-HT₃ RA, palonosetron (NEPA), simultaneously targets two critical antiemetic pathways, thereby offering a simple convenient antiemetic with long-lasting protection from CINV. This study is the first head-to-head NK₁ RA comparative study in patients receiving anthracycline cyclophosphamide (AC) and non-AC moderately emetogenic chemotherapy (MEC).

MATERIALS AND METHODS

This was a pragmatic, multicenter, randomized, single-cycle, open-label, prospective study designed to demonstrate noninferiority of single-dose NEPA to a 3-day aprepitant regimen in preventing CINV in chemotherapy-naive patients receiving AC/non-AC MEC in a real-life setting. The primary efficacy endpoint was complete response (no emesis/no rescue) during the overall (0-120 hour) phase. Noninferiority was achieved if the lower limit of the 95% confidence interval (CI) of the difference between NEPA and the aprepitant group was greater than the noninferiority margin set at -10%.

RESULTS

Noninferiority of NEPA versus aprepitant was demonstrated (risk difference 9.2%; 95% CI, -2.3% to 20.7%); the overall complete response rate was numerically higher for NEPA (64.9%) than aprepitant (54.1%). Secondary endpoints also revealed numerically higher rates for NEPA than aprepitant.

CONCLUSION

This pragmatic study in patients with cancer receiving AC and non-AC MEC revealed that a single dose of oral NEPA plus DEX was at least as effective as a 3-day aprepitant regimen, with indication of a potential efficacy benefit for NEPA.

IMPLICATIONS FOR PRACTICE

In the absence of comparative neurokinin 1 (NK₁ ) receptor antagonist (RA) studies, guideline committees and clinicians consider NK₁ RA agents to be interchangeable and equivalent. This is the first head-to-head study comparing one NK₁ RA (oral netupitant/palonosetron [NEPA]) versus another (aprepitant) in patients receiving anthracycline cyclophosphamide (AC) and non-AC moderately emetogenic chemotherapy. Noninferiority of NEPA versus the aprepitant regimen was demonstrated; the overall complete response (no emesis and no rescue use) rate was numerically higher for NEPA (65%) than aprepitant (54%). As a single-dose combination antiemetic, NEPA not only simplifies dosing but may offer a potential efficacy benefit over the current standard-of-care.

Harmonization of practices between radiotherapy centres in the Nord and Pas-de-Calais regions (France): A three-year evaluation

PURPOSE

The delineation of volumes of interest can be a source of significant interobserver variability. The purpose of this study was to improve the homogeneity of delineation between oncologist-radiotherapists in the territorial departments of Nord and Pas-de-Calais (France) through discussions of clinical cases and the adoption of common published reference documents.

MATERIALS AND METHODS

All eleven radiotherapy centres in the Nord and Pas-de-Calais departments of France participated. The localizations assessed to date included prostate, head and neck, breast and brain cancers. For each localization, the junior or senior physician(s) in charge of pathology delineated the volumes of interest according to their usual practices. Validated indices, including the Dice similarity coefficient, were used to quantify the delineation differences. The anonymized results were presented at two to three annual meetings. A second delineation of the clinical cases was then carried out to quantify homogenization. An evaluation of dosimetry practices was also conducted for prostate cancer. Wilcoxon assay matched data were used.

RESULTS

Our work showed either satisfactory delineation concordance after the initial assessment or improved delineation concordance. For prostate cancer, the Dice similarity coefficient values were greater than 0.6 initially in two of the three clinical cases. For head and neck cancers, a statistically significant improvement was observed for only one of the clinical target volumes. More than half of the Dice similarity coefficient values were greater than 0.6 in the first comparison. The study of clinical cases of breast cancer allowed a homogenization of the delineation of five of the six lymph node clinical target volumes. The dosimetry study of prostate cancer allowed for a homogenization of practices.

CONCLUSION

This work makes it possible to harmonize the delineation practices around validated standards. An extension to the entire Hauts-de-France region is planned.

Near-Infrared Spectroscopy and Anharmonic Theory of Protonated Water Clusters: Higher Elevations in the Hydrogen Bonding Landscape

Near-infrared spectroscopy measurements are presented for protonated water clusters, H⁺(H₂O) _n, in the size range of n = 1-8. Clusters are produced in a pulsed-discharge supersonic expansion, mass selected, and studied with infrared laser photodissociation spectroscopy in the regions of 3600-4550 and 4850-7350 cm^-1. Although there is some variation with cluster size, the main features of these spectra are a broad absorption near 5300 cm^-1, a sharp doublet near 7200 cm^-1, as well as a structured absorption near 4100 cm^-1 for n ≥ 2. The vibrational patterns measured for the hydronium, Zundel, and Eigen ions are compared to those predicted by different forms of anharmonic theory. Second-order vibrational perturbation theory (VPT2) and a local mode treatment of the OH stretches both capture key aspects of the spectra but suffer understandable deficiencies in the quantitative description of band positions and intensities.

Human adult bone marrow-derived somatic cell therapy results in functional recovery and axonal plasticity following stroke in the rat

Stroke is the leading cause of adult disability in the United States. To date there is no satisfactory treatment for stroke once neuronal damage has occurred. Human adult bone marrow-derived somatic cells (hABM-SC) represent a homogenous population of CD49c/CD90 co-positive, non-hematopoietic cells that have been shown to secrete therapeutically relevant trophic factors and to support axonal growth in a rodent model of spinal cord injury. Here we demonstrate that treatment with hABM-SC after ischemic stroke in adult rats results in recovery of forelimb function on a skilled motor test, and that this recovery is positively correlated with increased axonal outgrowth of the intact, uninjured corticorubral tract. While the complete mechanism of repair is still unclear, we conclude that enhancement of structural neuroplasticity from uninjured brain areas is one mechanism by which hABM-SC treatment after stroke leads to functional recovery.

Is There a Role for Pelvic Irradiation in Localized Prostate Adenocarcinoma? Preliminary Results of GETUG-01

Purpose

To assess the benefit and toxicity and quality-of-life (QOL) outcomes of pelvic nodes irradiation in nonmetastatic prostate carcinoma patients.

Patients and Methods

Between December 1998 and June 2004, 444 patients with T1b-T3, N0 pNx, M0 prostate carcinoma were randomly assigned to either pelvic and prostate radiotherapy or prostate radiotherapy only. Patients were stratified according to the prognostic factor of lymph node involvement (LNI). Short-term 6-month neoadjuvant and concomitant hormonal therapy was allowed only for patients in the high-risk group. The pelvic dose was 46 Gy. The total dose recommended to the prostate was changed during the course of the study from 66 Gy to 70 Gy. Criteria for progression-free survival (PFS) included biologic prostate-specific antigen recurrences or a local or metastatic evolution. Acute and late toxicities were recorded according to the Radiation Therapy Oncology Group and Late Effects in Normal Tissues Subjective, Objective, Management, and Analytic scales, respectively. The QOL outcome was recorded with the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire C30, the International Prostatic Symptom Score, and the Sexual Function Index scales.

Results

With a 42.1-month median follow-up time, the 5-year PFS and overall survival were similar in the two treatment arms for the whole series and for each stratified group. On multivariate analysis, low LNI risk and hormonal therapy were statistically associated with increased PFS. However, subgroup analyses based on these factors did not show any benefit for pelvic irradiation. There were no significant differences in acute and late digestive toxicities and in QOL outcomes.

Conclusion

Pelvic node irradiation was well tolerated but did not improve PFS.

Microwave emissions from police radar

This study evaluated police officers' exposures to microwaves emitted by traffic radar units. Exposure measurements were taken at approximated ocular and testicular levels of officers seated in patrol vehicles. Comparisons were made of the radar manufacturers' published maximum power density specifications and actual measured power densities taken at the antenna faces of those units. Four speed-enforcement agencies and one transportation research institute provided 54 radar units for evaluation; 17 different models, encompassing 4 frequency bands and 3 antenna configurations, were included. Four of the 986 measurements taken exceeded the 5 mW/cm2 limit accepted by the International Radiation Protection Association and the National Council on Radiation Protection and Measurement, though none exceeded the American Conference of Governmental Industrial Hygienists, American National Standards Institute, Institute of Electrical and Electronic Engineers, or Occupational Safety and Health Administration standard of 10 mW/cm2. The four high measurements were maximum power density readings taken directly in front of the radar. Of the 812 measurements taken at the officers' seated ocular and testicular positions, none exceeded 0.04 mW/cm2; the highest of these (0.034 mW/cm2) was less than 1% of the most conservative current safety standards. High exposures in the limited region directly in front of the radar aperture are easily avoided with proper training. Results of this study indicate that police officer exposure to microwave radiation is apparently minimal. However, because of uncertainty in the medical and scientific communities concerning nonionizing radiation, it is recommended that law enforcement agencies implement a policy of prudent avoidance, including purchasing units with the lowest published maximum power densities, purchasing dash/rear deck-mounted units with antennae mounted outside the patrol vehicle, and training police officers to use the "stand-by" mode when not actually using radar.

Stimulation of neonatal and adult brain neurogenesis by subcutaneous injection of basic fibroblast growth factor

Mounting evidence indicates that extracellular factors exert proliferative effects on neurogenetic precursors in vivo. Recently we found that systemic levels of basic fibroblast growth factor (bFGF) regulate neurogenesis in the brain of newborn rats, with factors apparently crossing the blood-brain barrier (BBB) to stimulate mitosis. To determine whether peripheral bFGF affects proliferation during adulthood, we focused on regions in which neurogenesis persists into maturity, the hippocampus and the forebrain subventricular zone (SVZ). In postnatal day 1 (P1) rats, 8 hr after subcutaneous injection (5 ng/gm body weight), bFGF increased [(3)H]thymidine incorporation 70% in hippocampal and SVZ homogenates and elicited twofold increases in mitotic nuclei in the dentate gyrus and the dorsolateral SVZ, detected by bromodeoxyuridine immunohistochemistry. Because approximately 25% of proliferating hippocampal cells stimulated in vivo expressed neuronal traits in culture, bFGF-induced mitosis may reflect increased neurogenesis. bFGF effects were not restricted to the perinatal period; hippocampal DNA synthesis was stimulated by peripheral factor in older animals (P7-P21), indicating the persistence of bFGF-responsive cells and activity of peripheral bFGF into late development. To begin defining underlying mechanisms, pharmacokinetic studies were performed in P28 rats; bFGF transferred from plasma to CSF rapidly, levels rising in both compartments in parallel, indicating that peripheral factor crosses the BBB during maturity. Consequently, we tested bFGF in adults; peripheral bFGF increased the number of mitotic nuclei threefold in the SVZ and olfactory tract, regions exhibiting persistent neurogenesis. Our observations suggest that bFGF regulates ongoing neurogenesis via a unique, endocrine-like pathway, potentially coordinating neuron number and body growth, and potentially providing new approaches for treating damaged brain during development and adulthood.

High-dose methotrexate for the treatment of primary cerebral lymphomas: analysis of survival and late neurologic toxicity in a retrospective series

PURPOSE

The impact of treatment options on survival and late neurologic toxicity was investigated in a series of patients with primary cerebral lymphoma (PCL) and no known cause of immunosuppression.

PATIENTS AND METHODS

Prognostic factors for survival and treatment-induced late neurotoxicity were investigated in a retrospective series of 226 patients with PCL.

RESULTS

With a median follow-up of 76 months, the median overall survival was 16 months and 5-year survival was 19%. In a univariate analysis, age greater than 60 years, performance status, CSF protein level greater than 0.6 g/L, involvement of corpus callosum or subcortical grey structures, detectable lymphoma cells in CSF, increased serum lactate dehydrogenase (LDH), but not histological subtype, were significantly correlated with a poor survival. Treatment with chemotherapy versus radiotherapy alone (P = .05), high-dose methotrexate (HDMTX; P = .0007), and cytarabine (P = .04) correlated with a better survival in univariate analysis. Using the Cox model, age, performance status, and CSF protein were independently correlated with survival. After adjustment of these factors, treatment with an HDMTX-containing regimen remained the only treatment-related factor independently correlated with survival (P = .01). The projected incidence of treatment-induced late neurotoxicity was 26% at 6 years in this series, with a median survival from the diagnosis of late neurotoxicity of 12 months. Treatment with radiotherapy followed by chemotherapy was the only parameter correlated with late neurotoxicity in multivariate analysis (relative risk, 11.5; P = .0007).

CONCLUSION

Patients with PCL treated with regimens that included HDMTX followed by radiotherapy have an improved survival, but not a higher risk of late neurotoxicity as compared with other treatment modalities in this series.

Cerebellar granule cells elaborate neurites before mitosis

Neuronal birth and neurite outgrowth have been regarded as discrete, sequential stages of development. However, we recently found that sympathetic neuroblasts often elaborate axons before mitosis, in culture [E. Wolf, I.B. Black, E. DiCicco-Bloom, Mitotic neuroblasts determine neuritic patterning of progeny, J. Comp. Neurol. 367 (1996) 623-635] and in vivo [E. Wolf, I.B. Black, E. DiCicco-Bloom, Central and peripheral neuroblasts elaborate neurites prior to division in vivo and in vitro, Soc. Neurosci. Abstr. 21 (1995) 785; E. Wolf, I.B. Black, E. DiCicco-Bloom, Mitotic neuroblasts engage in axonal outgrowth and pathfinding in vivo, Soc. Neurosci. Abstr. 22 (1996) 525]. Here, we report that cerebellar granule cells often divide with heritable neurites in vitro. Therefore, mitotic CNS precursors, in addition to peripheral neuroblasts, simultaneously undergo proliferation and process formation. Potentially, neurites on dividing precursors may allow target fields to influence directly the course of neurogenesis.

Epididymal cystadenomas in von Hippel-Lindau disease

OBJECTIVES

Epididymal cystadenomas (ECs) are frequently found in association with von Hippel-Lindau disease (VHL), but little has been reported about their sonographic appearance. We review the sonographic appearance of ECs, the relationship of ECs to other manifestations of VHL, and the specific genetic mutations associated with ECs.

METHODS

Fifty-six male patients with VHL were examined with scrotal sonography and physical examination as part of a larger screening program for VHL. The head of the epididymis was measured in two planes on sonography and compared with age-matched normal controls. All VHL patients with palpable epididymal abnormalities or enlargement (more than two standard deviations) of the head of the epididymis on ultrasound were considered positive for EC.

RESULTS

Thirty of 56 (54%) male patients with VHL demonstrated a unilateral (n = 10; 33%) or bilateral (n = 20; 67%) solid abnormality in the head of the epididymis suggestive of EC. Sonographic appearances ranged from a solid mass with multiple tiny cysts to an almost completely solid mass. The most common appearance was a 15- to 20-mm solid mass with small cystic components. Dilated efferent ductules were seen within the testicle in 7 men, evidently a result of chronic obstruction. There was no association between the clinical subtype of VHL and the presence of ECs (P > 0.10, chi square). Mutations resulting in a truncated gene product were associated with the development of ECs but the association did not reach statistical significance (P = 0.06).

CONCLUSIONS

ECs are a common manifestation of VHL in men and exhibit a range of appearances on ultrasound. Sonography can be used to identify ECs and determine the extent of cystic dilation of the rete testes. The benign course of ECs and the usual absence of clinical symptoms favor a conservative approach to their management.

Alanine-ESR in vivo dosimetry: a feasibility study and possible applications

A new alanine-ESR dosimeter has been developed at AERIAL in order to study its potential use in radiotherapy. Alanine-ESR results are compared with ion chamber for depth-dose measurements. A good concordance has been found between provisional dosimetry and absorbed dose during high dose rate and intra operative treatments. The results of the experiments indicate that alanine-ESR dosimetry is suited to check dose optimisation routines and seems to be a promising in vivo dosimetry technique.

[Iodine 125 curietherapy of choroidal melanomas. Values of the technique and initial results]

PURPOSE

Among conservative treatment of the choroidal melanoma, improved functional capacities can be provided with Iodine 125 and with a treatment planning system for optimized dosimetry.

METHODS

Forty patients were treated with Iodine 125 with a minimal follow-up period of 6 months and a mean follow up of 25 months.

RESULTS

Response to the treatment based on tumor regression or stabilization was 97%. Complication rate was 32%. Retinopathy was the major cause of loss of vision and was linked to the proximity of the tumor to the macula. Two patients developed metastasis and one required enucleation for tumor regrowth.

CONCLUSION

Brachytherapy with Iodine 125 was found to be effective on tumor growth within the limits of the follow-up. High doses (100 Gy) given to the apex of the tumor did not increase complications rate. Many years will be necessary to assess efficiency of such a procedure in terms of preventing complications.

Role of presynaptic input in the ontogeny of adrenergic cell signaling in rat brain: beta receptors, adenylate cyclase and c-fos protooncogene expression

Neurotransmitters act as trophic factors during brain development, regulating expression of genes that control cellular differentiation. One example of this trophism is the beta adrenergic signaling cascade: activation of beta receptors leads sequentially to increased cyclic AMP (cAMP), augmented expression of the nuclear transcription factor, c-fos, and induction of ornithine decarboxylase (ODC), an enzyme obligatory for neuronal development. After neonatal lesioning of noradrenergic nerves with 6-hydroxydopamine (6-OHDA), beta receptors become uncoupled from ODC induction in the cerebellum, a region that undergoes its peak of cell replication/differentiation postnatally. The present study investigates the mechanism for uncoupling of beta receptors from response elements. In the cerebellum, 6-OHDA had minor effects on beta receptor binding capabilities and caused slight supersensitivity of the beta adrenergic response of adenylate cyclase; the latter reflected increased expression of cyclase catalytic subunits, rather than a specific effect on beta receptor coupling. In contrast, the linkage of cAMP to cerebellar c-fos expression showed marked deficiencies in lesioned animals and a corresponding loss of the ability of beta receptors to induce c-fos; accordingly, this is a likely point at which beta adrenergic control of ODC is programmed by neuronal input. A critical period exists for neurotrophic influence: the alterations persisted past the point at which cerebellar norepinephrine levels recovered, and comparable effects did not occur in earlier-developing regions. In the forebrain, for example, neonatal lesions produced receptor upregulation and supersensitivity of c-fos to cAMP stimulation. These results suggest that presynaptic input is vital in programming beta adrenergic responsiveness during a critical period of development, and that interruption of transsynaptic events occurring at this time can lead to lasting alterations in neuronal differentiation and responsiveness.

Increased DNA-bending activity and higher affinity DNA binding of high mobility group protein HMG-1 prepared without acids

Recently, DNA ring closure assays showed that high mobility group protein HMG-1 and its close homolog HMG-2 mediate sequence-independent DNA flexion. This DNA-bending activity appears to be central to at least some of the recently elucidated functions of HMG-1/2, such as the enhancement of progesterone receptor DNA binding. Here we show that standard purification procedures utilizing perchloric and trichloroacetic acid can produce HMG-1 significantly deficient in its abilities to bind and bend double-stranded DNA, while acid-independent methods purify HMG-1 that is superior in these respects. Significant losses of DNA ring closure activity were seen upon limited 2-5-h exposures of nonacid-purified HMG-1/2 to perchloric acid and/or trichloroacetic acid. Measurements of the apparent DNA dissociation binding constant (Kd(app)) of acid-extracted preparations of HMG-1 gave a wide range of values, and only those preparations demonstrating little DNA ring closure activity had Kd values near the previously published value (approximately 10(-6) M). The highest ring closure activities and lowest Kd(app) (< 3 x 10(-9) M) were obtained for HMG-1 purified without acids. These combined results support the use of alternative, non-acid purification procedures for preserving the DNA-bending activity of HMG-1/2 and suggest that past procedures utilizing acids have led to an underestimation of the affinity of HMG-1 for DNA.

Multivariate analysis of prognostic factors in adult patients with medulloblastoma. Retrospective study of 156 patients

BACKGROUND

Medulloblastoma is a rare disease in adult patients, with an annual incidence rate of 0.05 per 100,000 per year. Results are, therefore, sparse and comprise small series over long periods. The real survival rate, the prognostic factors, the optimal postoperative radiation dose, and the role of adjuvant chemotherapy are still unknown for this disease in adults.

METHODS

The authors collected 156 cases of histologically proven medulloblastoma in patients older than 18 years of age who were treated between January 1975 and December 1991 in 13 French institutions. They analyzed the prognostic factors for survival and the impact of postoperative treatment on survival.

RESULTS

The 5- and 10-year event free survival rates, 61 and 48%, respectively, are similar to those observed in children. The median time to recurrence is 30 months, but late relapses after 5 years remain frequent. Multivariate analysis identified postoperative performance status, spinal axis radiation dose, fourth ventricular floor involvement, and desmoplastic histologic subtype as factors significantly correlated with event free survival. No benefit of concomitant chemotherapy was demonstrated, and complete resection resulted only in severely reduced postoperative performance status.

CONCLUSIONS

The prognostic factors in adult medulloblastoma are comparable to those of medulloblastoma in children, but a new parameter, postoperative performance status, was identified in this adult series. Postoperative craniospinal irradiation remains the standard treatment for adults with medulloblastoma. A reduced dose to the supratentorial compartment should be tested in a prospective protocol.

Role of thyroid status in the ontogeny of adrenergic cell signaling in rat brain: beta receptors, adenylate cyclase, ornithine decarboxylase and c-fos protooncogene expression

In adulthood, thyroid hormone regulates beta adrenergic responsiveness. We addressed whether similar processes operate in the developing brain, thus playing a role in neurotransmitter control of target cell differentiation. Rats were made hyperthyroid [triiodothyronine (T3)] or hypothyroid [propylthiouracil (PTU)] during the immediate perinatal period, and the development of beta adrenergic signal transduction was evaluated in three brain regions. PTU treatment resulted in an ubiquitous deficit in the number of beta receptor binding sites. Although beta adrenergic stimulation of adenylate cyclase activity was also obtunded by PTU, the effects were much less prominent and were restricted to one region (forebrain); comparison with basal adenylate cyclase and with total enzymatic activity (forskolin stimulation) indicated that the differences in isoproterenol response were at the level of adenylate cyclase expression, rather than in specific receptor coupling. PTU also reduced responsiveness of ornithine decarboxylase (ODC), a key enzyme that couples receptors to differentiation, again, changes in receptor-mediated responsiveness reflected alterations in total enzyme activity, rather than effects on receptor coupling. In contrast, measurements of c-fos, a protooncogene that couples cyclic AMP to induction of ODC, showed increased responses to beta adrenergic or cyclic AMP stimulation in PTU-treated animals. The effect of PTU on c-fos responsiveness occurred in the absence of alterations in basal c-fos expression, a situation different from that seen with adenylate cyclase or ODC. T3 administration had only small effects on any of these variables. The role of thyroid hormones thus involves targeting of beta receptors and receptor-mediated stimulation of nuclear transcription factors (c-fos), as well as basal expression of transduction components in the signalling cascade (adenylate cyclase, ODC). The effects of PTU, contrasted with the failure of T3 to enhance development of beta receptors or their transduction components, suggest that thyroid hormone is obligatory for normal development of this pathway, but that endogenous hormone levels are already optimally permissive.

beta Adrenergic control of c-fos protooncogene expression in developing rat brain regions

The protooncogene c-fos encodes a nuclear protein that acts as a powerful enhancer of gene transcription, and shares the same general patterns of reactivity to stimulation as ornithine decarboxylase, an essential enzyme in cell replication and differentiation; c-fos enhances expression of proteins whose genes possess the AP-1 consensus sequence, which include ornithine decarboxylase. In the current study, we examined the regulation of c-fos during early postnatal development of the rat central nervous system. Regional profiles of basal c-fos mRNA paralleled the ontogenetic profiles of cell replication and differentiation; in the earliest developing region (midbrain + brainstem) c-fos was low by birth and did not change over the first 2 postnatal weeks; in the forebrain, where replication and differentiation peak somewhat later, c-fos levels were higher during the first postnatal week than in the second; in the latest developing region (cerebellum), basal c-fos expression was low at birth and increased markedly during the second postnatal week, coincidentally with the increase in neuronal cell replication/differentiation. The resemblance of these patterns to those of ornithine decarboxylase, which is regulated in part by beta adrenergic input, led us to evaluate the potential role of beta receptors in the ontogenetic control of c-fos. In the forebrain of 2-day-old rats, intracisternal administration of isoproterenol, a beta adrenergic agonist, produced > 20-fold stimulation of c-fos within 10 min of drug administration. The induction was mediated through the beta receptor, as confirmed by studies with selective adrenergic blocking agents, and could be reproduced by administration of cAMP analogs.(ABSTRACT TRUNCATED AT 250 WORDS)

The DNA-bending protein HMG-1 enhances progesterone receptor binding to its target DNA sequences

Steroid hormone receptors are ligand-dependent transcriptional activators that exert their effects by binding as dimers to cis-acting DNA sequences termed hormone response elements. When human progesterone receptor (PR), expressed as a full-length protein in a baculovirus system, was purified to homogeneity, it retained its ability to bind hormonal ligand and to dimerize but exhibited a dramatic loss in DNA binding activity for specific progesterone response elements (PREs). Addition of nuclear extracts from several cellular sources restored DNA binding activity, suggesting that PR requires a ubiquitous accessory protein for efficient interaction with specific DNA sequences. Here we have demonstrated that the high-mobility-group chromatin protein HMG-1, as a highly purified protein, dramatically enhanced binding of purified PR to PREs in gel mobility shift assays. This effect appeared to be highly selective for HMG-1, since a number of other nonspecific proteins failed to enhance PRE binding. Moreover, HMG-1 was effective when added in stoichiometric amounts with receptor, and it was capable of enhancing the DNA binding of both the A and B amino-terminal variants of PR. The presence of HMG-1 measurably increased the binding affinity of purified PR by 10-fold when a synthetic palindromic PRE was the target DNA. The increase in binding affinity for a partial palindromic PRE present in natural target genes was greater than 10-fold. Coimmunoprecipitation assays using anti-PR or anti-HMG-1 antibodies demonstrated that both PR and HMG-1 are present in the enhanced complex with PRE. HMG-1 protein has two conserved DNA binding domains (A and B), which recognize DNA structure rather than specific sequences. The A- or B-box domain expressed and purified from Escherichia coli independently stimulated the binding of PR to PRE, and the B box was able to functionally substitute for HMG-1 in enhancing PR binding. DNA ligase-mediated ring closure assays demonstrated that both the A and B binding domains mediate DNA flexure. It was also demonstrated in competition binding studies that the intact HMG-1 protein binds to tightly curved covalently closed or relaxed DNA sequences in preference to the same sequence in linear form. The finding that enhanced PRE binding was intrinsic to the HMG-1 box, combined with the demonstration that HMG-1 or its DNA binding boxes can flex DNA, suggests that HMG-1 facilitates the binding of PR by inducing a structural change in the target DNA.

Radiation therapy in the conservative treatment of carcinoma of the anal canal

PURPOSE

Radiotherapy is the standard treatment of anal canal carcinoma. We retrospectively analyzed our experience with 108 patients. Special attention was given in evaluating 51 patients who received concomitant chemotherapy with 5-FU-CDDP.

METHODS AND MATERIALS

From January 1980 to December 1989, 108 patients with anal canal carcinoma were treated with exclusive radiotherapy at the Centre Hospitalier Lyon Sud. There were 11 men and 97 women, mean age was 65 years (30-86). Histologic types were 94 epidermoid carcinomas, 13 basaloid carcinomas, and one adenocarcinoma. The TNM classification (UICC 87) was: 16 T1 (14.8%), 53 T2 (49%), 33 T3 (39.5%), six T4 (5.5%), 77 N0 (71.3%), 20 N1 (18.5%), nine N2 (8.3%) and two N3 (1.8%). Papillon's radiotherapy technique with a Cobalt direct perineal field was used in 82 patients. Ninety-six patients were treated with an interstitial 192Ir implant with a mean delay of 55 days after the end of the radiotherapy. In 59 patients at least one course of either 5-FU-mitomycin (8) or 5-FU-CDDP was added with at least one course concomitantly to the radiotherapy in 53 patients.

RESULTS

A complete response in 104/108 patients (96%) was obtained 2 months after the brachytherapy. A locoregional relapse (local and/or pelvic failure) was seen in 18 patients (16.6%) and inguinal node relapse in nine (8.3%). Eight patients with locoregional recurrence and five with inguinal relapse were salvaged. A systemic failure occurred in six (5.5%) patients. Twenty-nine patients died, 16 of progressive disease. One patient died of treatment related toxicity. The overall 5-year survival was 64% +/- 6 and specific survival 72% +/- 8. None of the patient parameters was found to be statistically significant but there was a trend toward longer 5-year survival in T1-T2 patients and in those with well or moderately differentiated tumors. Noteworthy are the same survival rates for N0 and N1-N3 patients (65 vs. 62%). The objective response and the locoregional failure rates were similar in the patients treated with or without chemotherapy. The difference did not reach statistical significance though it was important for the following parameters: overall survival rates for T1-T2 with and without chemotherapy (94 vs. 61%) and for N1-3 patients (73% vs. 27%). The main prognostic factors in this series were differentiation (5-year overall survival with chemotherapy 95% vs. 27% without chemotherapy p = 0.02) and the response at 3 months after treatment initiation, before brachytherapy implant (5-year overall survival for complete responders and "very good responders" 71% vs. 34% in partial responders p = 0.002). The complications rate was acceptable (Grade III 9%, Grade II 14%). Anal preservation was possible in 85% of the patients (92/108). Nine abdominoperineal resection were performed for recurrence and seven for severe necrosis. The T3-T4 group abdomino perineal resection was 23% while it was 9.2% of the T1-T2 group.

CONCLUSION

We confirm that exclusive radiotherapy is the treatment of choice for epidermoid carcinomas of the anal canal. The role of chemotherapy is still unclear.

Bidirectional modulation of GABA-gated chloride channels by divalent cations: inhibition by Ca2+ and enhancement by Mg2+

The effects of the divalent cations Ca2+, Sr2+, Ba2+, Mg2+, Mn2+, and Cd2+ were studied on gamma-aminobutyric acidA (GABAA) responses in rat cerebral cortical synaptoneurosomes. The divalent cations produced bidirectional modulation of muscimol-induced 36Cl- uptake consistent with their ability to permeate and block Ca2+ channels. The order of potency for inhibition of muscimol responses was Ca2+ > Sr2+ > Ba2+, similar to the order for permeation of Ca2+ channels in neurons. The order of potency for enhancement of muscimol responses was Cd2+ > Mn2+ > Mg2+, similar to the order for blockade of Ca2+ channels in neurons. Neither Ca2+ nor Mg2+ caused accumulation of GABA in the extravesicular space due to increased GABA release or decreased reuptake of GABA by the synaptoneurosomes. The inhibition of muscimol responses by Ca2+ was most likely via an intracellular site of action because additional inhibition could be obtained in the presence of the Ca2+ ionophore, A23187. This confirms electrophysiologic findings in cultured neurons from several species. In contrast, the effects of Cd2+, Mn2+, and Mg2+ may be mediated via blockade of Ca2+ channels or by intracellular sites, although the results of these studies do not distinguish between the two loci. The effects of Zn2+ were also studied, because this divalent cation is reported to have widely divergent effects on GABAA responses. In contrast to other studies, we demonstrate that Zn2+ inhibits GABAA responses in an adult neuronal preparation. Zn2+ produced a concentration-dependent inhibition (limited to 40%) of muscimol responses with an EC50 of 60 microM. The inhibition of muscimol-induced 36Cl- uptake by Zn2+ was noncompetitive.(ABSTRACT TRUNCATED AT 250 WORDS)

Medulloblastoma in adults: survival and prognostic factors

The authors report a series of 30 adults with medulloblastoma treated after surgery between 1975 and 1990. Half the patients presented a classical medulloblastoma and the other half presented desmoplastic medulloblastoma. Brainstem infiltration was noted in 3 patients, cerebellar peduncle infiltration in 6 cases and 4 patients had cerebrospinal fluid (CSF) involvement. Tumor resection was achieved in all patients except 1, and in 5 surgery was incomplete. All patients but 2 received postoperative cerebral radiotherapy. Six patients did not receive chemotherapy before radiotherapy, 7 patients received CCNU-Vincristine concomitantly with and after irradiation, 1 patient was given a CHOP regimen, and the remaining 16 patients received the 8 drugs in a 1-day (8/1) regimen before irradiation. The median follow-up time was 104 months. The 5- and 10-year overall survival rates were 58.5% and 41%, respectively. Two toxic deaths occurred under the 8/1 regimen, and no better survival was observed for this group of patients in comparison with those receiving other regimens. Persistence of malignant cells in the CSF, brainstem involvement, cerebellar peduncle infiltration, non-radical surgery and a postoperative performance status (PS) of more than 2 were significantly correlated with an adverse outcome for overall survival in adult patients with medulloblastoma.

Expression of P-glycoprotein restricted to normal cells in neuroblastoma biopsies

Immunohistological detection of P-glycoprotein (P-gp) with monoclonal antibody C219 was performed on serial sections of 37 neuroblastoma specimens representative of the different forms of the disease, from stage 1 ganglioneuroma to stage 4 neuroblastoma. Malignant cells, irrespective of their degree of maturation varying from neuroblasts to ganglion cells, were negative on all specimens. The expression of P-glycoprotein was detected in nine specimens, but it was restricted to normal cells within the tumour. In four specimens, C219 reacted with normal infiltrating cells in the stroma (i.e. monocytes, histiocytes or fibroblasts) representing 5 to 10% of the total population within the section; in three specimens, the residual adrenal gland was strongly positive, and in two ganglioneuromas, a weak reactivity of C219 was observed on a few satellite cells and schwann cells. Three of 15 biopsies obtained at diagnosis contained normal P-gp positive cells: two were classified as stage 1 ganglioneuromas; one was a typical stage 4 composite tumours with positive histiocytes and fibroblasts in the well-differentiated counterpart. Six of 22 biopsies obtained after patients had received our current protocol of chemotherapy contained normal P-gp positive cells: five were partially differentiated and necrotic under the effect of chemotherapy; only one positive specimen was classified as undifferentiated neuroblastoma. Among negative specimens from previously treated patients, one was obtained from a patient in relapse after high-dose chemotherapy and ABMT, two were obtained from patients who had not responded to induction therapy, and six from patients in partial remission after induction therapy. The clinical evolution was very similar in both groups of patients with P-gp negative or positive biopsies. These findings suggest that the quantitative assessment of MDR RNA by northern blotting on fresh homogenates is likely to overestimate its expression on neuroblastoma cells, and that the mechanism of chemoresistance in widespread neuroblastoma is less likely to be associated with P-gp expression.

Presynaptic input regulates development of beta-adrenergic control of rat brain ornithine decarboxylase: effects of 6-hydroxydopamine or propranolol

beta-Adrenergic control of ornithine decarboxylase (ODC) activity is exerted only during a critical period in central nervous system development, playing an important role in neurotransmitter modulation of cell replication and differentiation. The current study examines the effects of lesions caused by 6-hydroxydopamine administration to neonatal rats, or of gestational exposure to propranolol, on the subsequent development of the ODC response to beta-adrenergic stimulation elicited by an acute intracisternal challenge with isoproterenol. 6-Hydroxydopamine treatment severely attenuated the ability of isoproterenol to stimulate ODC in the cerebellum, a tissue that shows a postnatal peak of ODC reactivity. In contrast, much smaller effects were seen in the cerebral cortex, which has an earlier (pre/perinatal) peak of ODC, despite the fact that norepinephrine depletion was more persistent in the cortex. On the other hand, blockade of fetal beta-receptors by maternal propranolol infusions resulted in immediate postnatal attenuation of the ODC response in cerebral cortex, but not cerebellum. These data suggest that early exposure of beta-receptors to norepinephrine "programs" the subsequent efficiency of the receptor linkage to ODC during a critical ontogenetic period that occurs prenatally in the cerebral cortex and postnatally in the cerebellum.

Early developmental exposure to benzodiazepine ligands alters brain levels of thiobarbituric acid-reactive products in young adult rats

Levels of thiobarbituric acid (TBA)-reactive material were measured in brain regions of 3-4 month-old rats following prenatal exposure to several benzodiazepine (BDZ) receptor ligands over gestational days 14-20. Prenatal exposure to diazepam (DZ) at 1.0 mg/kg/day markedly elevated levels of brain TBA-reactive material while exposure to a higher dose (2.5 mg/kg) induced a significant increase only in the hippocampus. Early exposure to the central-type BDZ agonist clonazepam as well as to the central-type antagonist Ro 15-1788 also increased brain levels of TBA-reactive material. Concurrent exposure to the higher dose of DZ partially attenuated the effect of Ro 15-1788. Prenatal exposure to the peripheral-type BDZ ligand PK11195 produced a profound increase in TBA-reactive products in all regions, and concurrent DZ exposure did not attenuate this effect, except in the basal ganglia. Measurement of TBA-reactive material from birth to 3 months indicated that the effect of prenatal exposure to DZ was not apparent until after 8 weeks of age. Acute in vitro exposure of adult and fetal tissue to DZ had no effect on TBA-reactive material. The results suggest an interference in the organization of cellular metabolism in the brain by developmental exposure to BDZ ligands.

Effects of single cyclophosphamide doses on the kinetics of thoracic duct lymph and blood leukocytes in calves

After 5 or 20 mg cyclophosphamide per kg body weight, given once i.v., the output in thoracic duct lymph of small and large lymphoid cells, cells incorporating [3H]lymidine in vitro, mitotic cells, pyknotic cells, and/or the number of lymphocytes and neutrophils in peripheral blood were measured in six calves. The median grain count of labeled cells and the DNA content of pyknotic nucleic were determined. After both doses there was an exponential decrease and subsequent recovery of the median grain count. The larger dose caused a temporary cessation of lymphoid cell division, reduced the output of nondividing small lymphoid cells, and probably imparied proliferation of neutrophil precursors. The results suggest that increased cell production during recovery was due to changes in the growth fraction and that feedback mechanisms acting on G0-G1 cells controled the proliferation of lymphoid cells.