P11.15.B First multicentric real-life experience with the combination of lomustine and temozolomide in newly diagnosedMGMT promoter methylatedIDH wildtype glioblastoma

Background

The CeTeG/NOA-09 trial assessed in a randomized phase 3 setting, whether combined treatment of lomustine together with temozolomide was superior to temozolomide treatment alone in newly diagnosed MGMT (O(6)-methylguanine-DNA-methyltransferase) promoter methylated glioblastoma patients. Survival was significantly improved from 31.4 months with temozolomide alone to 48.1 months with the combination of lomustine plus temozolomide. In view of this encouraging data - suggesting this combination could have a significant impact on the survival of newly diagnosed glioblastoma patients - we were curious to assess safety and efficacy of this regimen under real-life conditions.

Material and Methods

We collected clinical and radiographic data from adult newly diagnosed MGMT promoter methylated IDH (isocitrate dehydrogenase) wildtype glioblastoma patients treated at five neuro-oncology centers in Germany. As a requirement for inclusion, first-line treatment with lomustine plus temozolomide had to be performed for at least six weeks (one course). The available radiographic data was independently reviewed by an experienced board-certified neuro-radiologist.

Results

In total, 70 patients were included. Median progression-free survival of the full cohort was 14.4 months and median overall survival was 36.0 months. Patients who received TTFields (Tumor Treating Fields) treatment for eight weeks or longer together with the combination of lomustine plus temozolomide (n=22, 31%) had a prolonged progression-free survival compared to those patients who received TTFields treatment less than eight weeks or did not receive treatment with TTFields (n=48, 69%) (21.5 months versus 11.2 months; HR: 2.118, 95% CI: 1.245-3.605; p=0.0105). In a multivariable Cox regression analysis the use of TTFields for eight weeks or longer together with the combination of lomustine plus temozolomide as well as the application of at least five courses of CeTeG therapy emerged as independent prognostic factors for progression-free survival and overall survival. Pseudoprogression occurred in n=16 (33%) of the patients. We observed no treatment related deaths and high-grade hematotoxicity in n=31 (44%) of the patients.

Conclusion

The results from this multicentric trial that investigated newly diagnosed MGMT promoter methylated IDH wildtype glioblastoma under real-life conditions indicate toxicity and survival estimates comparable to the CeTeG/NOA-09 trial. The use of TTFields for at least eight weeks in combination with this regimen was independently associated with extended progression-free and overall survival.

OS06.5.A Investigating safety and efficacy of TTFields prior and concomitant to radiotherapy in newly diagnosed glioblastoma - the PriCoTTF phase I/II trial

Background

The EF-14 phase III trial demonstrated improved survival for patients with newly diagnosed glioblastoma (nGBM) when TTFields therapy was added to adjuvant temozolomide chemotherapy. TTFields at 200 kHz are applied to the tumor utilizing arrays on the patients’ scalp. In preclinical studies, a synergistic inhibiting effect on glioblastoma cell proliferation was found for the combination of TTFields and radiotherapy. Based on these findings, we conduct the phase I/II PriCoTTF trial in adult nGBM patients to investigate the safety and efficacy of TTFields therapy initiated prior and concomitant to radiochemotherapy.

Material and Methods

Per study protocol, TTFields therapy is initiated following surgery and completed wound healing. Continuing throughout radiochemotherapy and adjuvant chemotherapy, TTFields therapy is used for approximately 9 months in total with TTFields rechallenge allowed at recurrence. Radiotherapy is conducted with arrays applied on the patients’ scalp. A total recruitment of 33 patients was sought, with 20 patients in arm A receiving normo-fractionated radiotherapy, and 13 elderly patients in arm B receiving hypo-fractionated radiotherapy. Safety and tolerance are the study’s primary endpoint, analyzed by a selection of pre-specified treatment-limiting toxicities (TLTs).

Results

A total of 33 patients have been enrolled. Patients' characteristics were mostly typical for glioblastoma, except for a rather low fraction of patients with gross total resection (GTR, 22.5%). The distribution of adverse events of common toxicity criteria (CTC) grade 3 or higher was comparable to that of established glioblastoma trials. Notably, skin toxicity of CTC grade 3 or higher was quite uncommon (n=2, 6%). As no patient developed TLTs, the study's primary endpoint was met. Median TTFields treatment duration was 8.4 months. Overall survival data was not mature enough (event rate 48%) to allow for a definite conclusion. Notably, on multivariable Cox regression, the number of days with TTFields adherence of more than 23 hours was independently associated with overall survival (HR 0.96, 95% confidence interval 0.93 - 0.99, p=0.008).

Conclusion

The PriCoTTF trial met its primary endpoint indicating that combined TTFields and radiotherapy is safe and well tolerated. High-grade skin toxicity was quite uncommon and the patients with high TTFields adherence seem to perform particularly well. An extended follow-up is required to provide first estimates regarding putative efficacy. At that point in time, the reduced overall TTFields duration and fraction of patients with GTR need to be factored in.

P17.04.B Combination of Trofosfamide and Etoposide in Recurrent Glioma

Background

Disease relapse almost inevitably occurs in patients with adult-type diffuse glioma. Standard of care treatment options at tumor relapse are still not well defined. Frequently used drugs for adult-type diffuse glioma recurrence include lomustine (CCNU) and bevacizumab. Few studies indicate that the combination of trofosfamide/etoposide, given their high lipid solubility with good blood-brain barrier penetrance, may be feasible in pediatric glioblastoma patients. In this retrospective analysis, we determined tolerability and feasibility of combined trofosfamide/etoposide treatment at disease recurrence of patients with adult-type diffuse glioma.

Material and Methods

We collected clinicopathological data from adult patients with adult-type diffuse glioma treated with the combination of trofosfamide/etoposide at the Division of Clinical Neurooncology at the University Hospital Essen. Only those patients were considered eligible who received trofosfamide/etoposide treatment for more than four weeks (one course). Trofosfamide (100mg/m2/day) and Etoposide (25mg/m2/day) was administered orally in a “one week on, one week off” scheme. A cohort of patients receiving empiric treatment at the investigators’ discretion balanced for tumor entity and canonical prognostic factors (number of previous treatments, MGMT promoter methylation, IDH mutation status, KPS, age, extent of resection) served as control. We collected toxicity data as it pertained to CTCAE (Common Terminology Criteria for Adverse Events, version 5.0) and survival data to explore putative efficacy.

Results

A total of 33 patients were eligible for this analysis. In the IDH wild-type glioblastoma (n=18) subgroup, median progression-free survival (3.8 months versus 2.9 months, HR: 2.09, 95% CI: 1.010-4.312, p=0.0227; PFS-6: 39% versus 6%) and median overall survival (10.4 months versus 5.7 months, HR: 3.05, 95% CI: 1.393-6.655, p=0.0008) were significantly prolonged as compared to the control cohort. In a multivariable Cox regression analysis, treatment with trofosfamide/etoposide emerged as statistically significant prognostic marker regarding progression-free survival and overall survival. We observed high-grade adverse events (CTCAE grade≥III ) in 21 (64%) of all recurrent glioma patients with hematotoxicity comprising most adverse events (n=18, 86%). Lymphopenia was by far the most observed hematotoxic adverse event (n=13, 62%). Among non-hematologic high-grade adverse events was transaminase elevation (n=3, 14%).

Conclusion

This study provides first indication that the combination of trofosfamide/etoposide is safe in patients with adult-type diffuse gliomas and may be associated with prolonged survival in adult patients with recurrent IDH wildtype glioblastoma. Our data provide a reasonable rationale for follow-up of a larger cohort in a prospective controlled trial.

P14.64 PriCoTTF Trial: A phase I/II trial of TTFields prior and concomitant to radiotherapy in newly diagnosed glioblastoma

BACKGROUND

TTFields therapy is applied at 200 kHz by arrays that are placed at the patients’ scalp. In the phase 3 EF-14 trial, survival rates were significantly improved when adding tumor-treating fields (TTFields) to adjuvant temozolomide-based chemotherapy in patients with newly diagnosed glioblastoma (nGBM). In preclinical studies, the combination of TTFields and radiotherapy synergistically impaired proliferation and growth of glioblastoma cells. Here, we present the PriCoTTF trial, which is enrolling nGBM patients and will assess the safety and efficacy of TTFields initiated prior and concomitant to radiochemotherapy.

MATERIAL AND METHODS

Following surgery and complete wound-healing, TTFields therapy is initiated in adult nGBM patients. TTFields therapy continues throughout radiochemotherapy and adjuvant chemotherapy for a total of approximately 9 months. During radiotherapy, the arrays - through which TTFields is delivered - remain on the patients’ scalp. Totally, thirty-three patients are planned to be enrolled in two treatment arms. In arm A, 20 patients receive normo-fractionated radiotherapy, whereas in the elderly arm, arm B, 13 patients receive hypo-fractionated radiotherapy. Concomitant and adjuvant chemotherapy follow institutional standards and interdisciplinary tumor conference recommendations.

RESULTS

The primary endpoint of this trial is safety and tolerance that will be gauged by a set of pre-specified treatment-limiting toxicities. Secondary endpoints include the frequency of adverse events, progression-free survival (PFS), and overall survival (OS). The trial is currently enrolling patients at four sites in Germany. At the time of abstract submission, 9 patients enrolled in Arm B. Patient recruitment for arm A has been completed with 20 patients enrolled. We will present initial practical experiences as well as preliminary safety and tolerance data.

CONCLUSION

There is a biological rationale for combining TTFields and radiotherapy to further improve survival of GBM patients. In the presented phase I/II trial, the safety and efficacy of TTFields initiated prior and concomitant to RT in nGBM will be assessed. In addition, initial efficacy data (phase II) may serve as a rationale for a putative randomized phase III trial.

[Spontaneous course of traumatic tympanic membrane perforations]

BACKGROUND

Traumatic eardrum perforation is a common presentation in otorhinolaryngologic practices and emergency clinics. A consistent management strategy (active intervention vs. watchful waiting) is, however, still lacking.

OBJECTIVE

In the following study, the outcome of watchful waiting is analyzed and presented.

MATERIALS AND METHODS

A collective of 272 patients presenting at two different specialist ENT practices within days of traumatic tympanic membrane perforation from June 2002 to March 2019 were analyzed. Treatment was non-surgical, with prospective monitoring. Whereas antibiotics were not given at all in one practice, they were given only upon signs of infection in the other practice. The outcome was evaluated retrospectively on the basis of patient files.

RESULTS

The collective consisted of 185 males and 87 females. Mean age was 30 years (range: 7 months to 82 years). The perforations were most commonly located in the upper anterior and lower posterior quadrants. According to Griffin grading, the size was grade I in 97%. The three most common causes were impact to the ear, barotrauma, and foreign bodies. Under a watchful waiting regimen, 95% of the patients presenting for follow-up checks showed complete closure.

CONCLUSION

Watchful waiting can be assessed as appropriate in traumatic eardrum perforation, provided otorhinolaryngologic follow-up is ensured. An exception is blast injury, which is now much less common in Central Europe, as this is associated with a risk of secondary cholesteatomas. In these rare cases, active treatment with surgical exploration of the middle ear including relining the perforation is indicated.

Combined radiotherapy and concurrent tumor treating fields (TTFields) for glioblastoma: Dosimetric consequences on non-coplanar IMRT as initial results from a phase I trial

Background

Glioblastoma is a rapidly proliferating tumor. Patients bear an inferior prognosis with a median survival time of 14-16 months. Proliferation and repopulation are a major resistance promoting factor for conventionally fractionated radiotherapy. Tumor-Treating-Fields (TTFields) are an antimitotic modality applying low-intensity (1-3 V/cm), intermediate-frequency (100-300 kHz) alternating electric-fields. More recently interference of TTFields with DNA-damage-repair and synergistic effects with radiotherapy were reported in the preclinical setting. This study aims at examining the dosimetric consequences of TTFields applied during the course of radiochemotherapy.

Methods

Cone-beam-computed-tomography (CBCT)-data from the first seven patients of the PriCoTTF-phase-I-trial were used in a predefined way for dosimetric verification and dose-accumulation of the non-coplanar-intensity-modulated-radiotherapy (IMRT)-treatment-plans as well as geometric analysis of the transducer-arrays by which TTFields are applied throughout the course of treatment. Transducer-array-position and contours were obtained from the low-dose CBCT’s routinely made for image-guidance. Material-composition of the electrodes was determined and a respective Hounsfield-unit was assigned to the electrodes. After 6D-fusion with the planning-CT, the dose-distribution was recalculated using a Boltzmann-equation-solver (Acuros XB) and a Monte-Carlo-dose-calculation-engine.

Results

Overdosage in the scalp in comparison to the treatment plan without electrodes stayed below 8.5% of the prescribed dose in the first 2 mm below and also in deeper layers outside 1cm² at highest dose as obtained from dose-volume-histogram comparisons. In the clinical target volume (CTV), underdosage was limited to 2.0% due to dose attenuation by the electrodes in terms of D95 and the effective-uniform-dose. Principal-component-analysis (PCA) showed that the first principal-position-component of the variation of repeated array-placement in the direction of the largest variations and the perpendicular second-component spanning a tangential plane on the skull had a standard deviation of 1.06 cm, 1.23 cm, 0.96 cm, and 1.11 cm for the frontal, occipital, left and right arrays for the first and 0.70 cm, 0.71 cm, 0.79 cm, and 0.68 cm, respectively for the second-principal-component. The variations did not differ from patient-to-patient (p > 0.8, Kruskal-Wallis-tests). This motion led to a diminution of the dosimetric effects of the electrodes.

Conclusion

From a dosimetric point of view, dose deviations in the CTV due to transducer-arrays were not clinically significant in the first 7 patients and confirmed feasibility of combined adjuvant radiochemotherapy and concurrent TTFields.

PriCoTTF Trial: A phase I/II trial of TTFields prior and concomitant to radiotherapy in newly diagnosed glioblastoma.

DRKS-ID: DRKS00016667.

Date of Registration in DRKS: 2019/02/26.

Investigator Sponsored/Initiated Trial (IST/IIT): yes.

Ethics Approval/Approval of the Ethics Committee: Approved.

(leading) Ethics Committee Nr.: 18–8316-MF, Ethik-Kommission der Medizinischen.

Fakultät der Universität Duisburg-Essen.

EUDAMED-No. (for studies acc. to Medical Devices act): CIV-18-08-025247.

Sequence-dependent cross-resistance of combined radiotherapy plus BRAFV600E inhibition in melanoma

INTRODUCTION

Treatment of patients with metastatic melanoma is hampered by drug-resistance and often requires combination with radiotherapy as last-resort option. However, also after radiotherapy, clinical relapses are common.

METHODS & RESULTS

Our preclinical models indicated a higher rate of tumour relapse when melanoma cells were first treated with BRAF^V600E inhibition (BRAFi) followed by radiotherapy as compared to the reverse sequence. Accordingly, retrospective follow-up data from 65 stage-IV melanoma patients with irradiated melanoma brain metastases confirmed a shortened duration of local response of mitogen-activated protein kinase (MAPK)-inhibitor-pretreated compared with MAPK-inhibitor-naïve intracranial metastases. On the molecular level, we identified JARID1B/KDM5B as a cellular marker for cross-resistance between BRAFi and radiotherapy. JARID1B^high cells appeared more frequently under upfront BRAFi as compared with upfront radiation. JARID1B favours cell survival by transcriptional regulation of genes controlling cell cycle, DNA repair and cell death.

CONCLUSION

The level of cross-resistance between combined MAPK inhibition and radiotherapy is dependent on the treatment sequence. JARID1B may represent a novel therapy-overarching resistance marker.

DNMT-dependent suppression of microRNA regulates the induction of GBM tumor-propagating phenotype by Oct4 and Sox2

Cancer stem-like cells represent poorly differentiated multipotent tumor-propagating cells that contribute disproportionately to therapeutic resistance and tumor recurrence. Transcriptional mechanisms that control the phenotypic conversion of tumor cells lacking tumor-propagating potential to tumor-propagating stem-like cells remain obscure. Here we show that the reprogramming transcription factors Oct4 and Sox2 induce glioblastoma cells to become stem-like and tumor-propagating via a mechanism involving direct DNA methyl transferase (DNMT) promoter transactivation, resulting in global DNA methylation- and DNMT-dependent downregulation of multiple microRNAs (miRNAs). We show that one such downregulated miRNA, miRNA-148a, inhibits glioblastoma cell stem-like properties and tumor-propagating potential. This study identifies a novel and targetable molecular circuit by which glioma cell stemness and tumor-propagating capacity are regulated.

Microbial and antibiotic resistant constituents associated with biological aerosols and poultry litter within a commercial poultry house

Poultry are known to harbor antibiotic resistant and pathogenic bacteria, and as such poultry litter and poultry house air can be contaminated with these bacteria. However, the presence of antibiotic resistant bacteria in biological aerosols and litter is largely not understood. The purpose of this study was to determine the amount of aerosolized bacteria and endotoxin, particularly fecal indicators, staphylococci, and enterococci, associated with poultry house and outdoor air. Aerosol samples were collected at multiple locations on the farm and in the house. Antibiotic resistance was investigated using the Kirby Bauer method on selected isolates using twelve different antibiotics spanning both narrow to broad spectrums of effectiveness. Overall there was a cyclical increase in bacterial concentrations as flocks progressed from pre-flock to late-flock, with >2 orders magnitude lower concentration during pre-flock periods (no chickens), in both the litter and aerosol samples. The house environment provided for significantly concentrated bacterial and endotoxin levels. It was estimated that Staphylococcus bacteria accounted for at least 90% of cultured aerobic bacteria and culture-independent 16S rRNA analyses demonstrated that significant population changes occurred from pre- to late-flock. Rarely was an isolate resistant to more than 4 antibiotic classes; however there was a trend upwards in overall resistance of enterococci as the flock cycle progressed. It appears that although levels of antibiotic resistant bacteria were highly concentrated within the house, levels were much lower outside of the house, and very little house escape occurred.

The use of open MRI in otorhinolaryngology: initial experience

Intraoperative imaging in head and neck surgery is a useful tool in many situations. In addition to being helpful for intraoperative orientation, real-time imaging enables visualization of the progress of surgery and the completeness of tumor resection. Regions in the head and neck to which access is difficult, and which therefore have a high incidence of morbidity and risk for the patient, can be approached more easily and safely in an open MRI than in a conventional way. Interventions in the open MRI (Signa SP, 0.5 Tesla) were performed with nonmagnetic instruments and an MR-safe microscope. For intraoperative navigation, the integrated FlashPoint system is helpful, because it allows targeting of the tumor by a calculated virtual line. T1W spin-echo, T2W fast spin-echo, and 3D T1W gradient-echo sequences were used for high-resolution imaging. Real-time imaging is achieved by fast multiplanar spoiled gradient-echo sequences or T2 single-shot fast spin-echo sequences. From 1996 to the present, we biopsied 17 petroclival tumors, performed paranasal sinus surgery in five cases, biopsied two neck masses, and inserted tubes for brachytherapy in 12 cases. No complications were observed. In all surgical procedures, a good resolution was obtained with MRI, especially for soft-tissue structures. The tumor could be targeted exactly, and all specimens revealed the relevant histology. In paranasal sinus surgery, however, the success rate was lower because it was difficult to distinguish blood from pathologic tissue. The insertion of tubes for brachytherapy was successful in all cases. It was possible to apply the tubes parallel to each other, 1 cm apart. Relevant biopsies could be taken of both neck masses. The indications for the use of open MRI in otorhinolaryngology are biopsies of tumors in regions that are difficult to approach, such as the petrous apex and petroclival region, the parapharyngeal space, and the orbit. Furthermore, the open MRI can be useful in paranasal sinus surgery, in the evaluation of tissue resection, and in the detection of the anatomy of delicate structures such as the internal carotid artery, the skull base, and the orbit. In addition, active navigation in the open MRI is possible with the integrated FlashPoint system. The advantage over conventional navigation systems lies in the possibility of real-time imaging, which allows detection of tissue changes occurring during the procedure.

Magnetic Resonance Imaging???Guided Biopsies of the Petrous Apex and Petroclival Region

OBJECTIVE

To analyze the advantages in safety and precision of biopsies of the petrous apex and petroclival region using open magnetic resonance imaging (MRI).

SETTING

The University of Leipzig Medical Center.

PATIENTS

Biopsies were taken in 13 patients with tumors of the petrous apex and petroclival region.

INTERVENTION

With the patient in the 0.5-T intraoperative MRI system (Signa SP; General Electric Medical Systems, Boston, MA, U.S.A.), biopsies were taken from the petrous apex and the petroclival region under imaging control by transseptal, transsphenoidal access. The region of interest was approached with a virtual pointer (Flashpoint Position Encoder; Image Guided Technologies, U.S.A.) and marked with a gadolinium-filled pointer.

RESULTS

In all patients, the authors obtained enough tissue for histologic study, which also proved to be the suspected tumor. One patient had a bone cyst, another had a malignant lymphoma, and another two a cholesterol granuloma originating from the petrous apex. Three other patients had metastases (carcinoma of the breast, bronchial carcinoma, and unknown origin). Three patients had a meningioma, and another three a chordoma. The authors did not see any postoperative complications.

CONCLUSIONS

In the authors' experience, the transsphenoidal access is favorable for approaching and sampling lesions of the petrous apex and the petroclival region. This route, however, is disadvantageous because the course of the internal carotid artery and the brainstem narrow the surgical space to the petrous apex. Open MRI in these cases is very useful because it allows a safe approach to the tumor by navigation and by visualizing the anatomic structures in real-time imaging.

Transnasal and transsphenoidal MRI-guided biopsies of petroclival tumors

Magnetic resonance imaging (MRI) allows excellent tissue characterization in the area of the petroclival region and can depict lesions not visualized with ultrasound or computed tomography (CT). The aim of this study was to demonstrate the clinical feasibility and utility of an interactive MR-guidance system to target and biopsy tumors in the petroclival region. MRI-guided biopsies of 10 patients with tumors in the clivus and petrous apex were performed in an open 0.5-T MR system. Lesions were targeted through a transsphenoidal or transnasal approach. Imaging during biopsies was achieved by a combination of standard and interactive mode. T1-weighted spin-echo, T2-weighted fast spin-echo (FSE), and three-dimensional T1-weighted gradient-echo (GRE) scans (standard mode) were selected to provide optimal tissue characterization for both the lesion and surrounding structures and varied according to the anatomic site. For interactive imaging, T1-weighted GRE and T2-weighted FSE sequences were used. We performed MRI-guided transsphenoidal biopsies in 10 patients who had lesions identified by CT (n = 5) and/or MRI (n = 10). The indications for biopsies were to differentiate between suspected malignant processes (n = 4 ) and benign processes (n = 6). Lesions adjacent to structures like the internal carotid artery were accurately targeted in particular. All biopsies were performed successfully and were the basis for selection of further treatment. No complications occurred during the procedures. An open MR system allows interactive control of biopsies in the area of the petroclival region, providing maximum patient safety and diagnostic accuracy not possible in other systems. The advantages of MRI tissue characterization are combined with an interactive, one-step method of localization and targeting, as well as tissue sampling. J. Magn. Reson. Imaging 2001;13:3-11.

RT-PCR amplification of mRNA from single brain neurospheres

A method is described that allows cDNA production from individual brain cell clones or 'neurospheres'. These culture-generated spheres of stem, progenitor, and differentiated cells have been the focus of interest because they represent an in vitro model of neurogenesis. However, because neurospheres are somewhat resistant, in part due to their enclosure by a dense extracellular matrix, to methods attempting to disrupt them and isolate nucleic acids, there is a need for new technology that affords the simple and efficient RT-PCR for studies of neural gene expression and discovery. A method is described here that uses sonication and an all-in-one approach for the construction of cDNA from single neurospheres. The generation of cDNA from individual adult brain stem/progenitor cell neurospheres is useful for future studies of neurogenic gene expression.

[Growth of human respiratory epithelium on collagen foil]

BACKGROUND

Clinical application of bioartificial tracheal prosthesis must still be regarded as an experimental concept because restoration of a functional respiratory epithelium outlining the prosthesis is still not possible. Tissue engineering as a relatively new biotechnological discipline may offer new methods in expanding differentiated respiratory epithelium in vitro. In this study we compare two different cell and tissue culture procedures for growing human nasal mucosa on commercially available collagen foil.

MATERIAL AND METHODS

Harvested specimens of human nasal mucosa (n = 6, 4 x 4 cm) were placed on collagen foil and incubated as tissue cultures for 4, 6 and 8 weeks. A suspension of enzymatically dispersed nasal epithelium seeded on collagen foil (5 x 10(5) cells) served as control. Cell growth and ciliary beat were monitored through an inverted microscope with Hoffman's modulation contrast and video set-up. Histological examination was performed after 4, 6 and 8 weeks.

RESULTS

In the tissue cultures, the collagen foil was initially covered with fibroblasts growing from the mucosa specimen before epithelial cells spread out. The epithelial layer showed mostly ciliated cells which developed metachronous ciliary beat after 4 weeks in vitro. Ciliary activity was observed until the end of the experiments in 8 weeks. New cells on the suspension cultures were mesenchymal and did not exhibit any ciliary activity.

CONCLUSIONS

Mucosa specimens seem to be more appropriate for tissue engineering of respiratory epithelium than cell suspensions from nasal epithelium. Collagen foil as tissue scaffold initiates epithelial-mesenchymal interaction and may play an important role in epithelial differentiation of new respiratory epithelium.

[Use of open MRI in head-neck surgery]

The vertical open MRI (Signa SP, 0, 5 Tesla) is ideal for interventional diagnosis and therapy. From our point of view indications in Otorhinolaryngology are biopsies of tumours which are difficult to access such as the petrous apex and the petroclival region, the parapharyngeal space and neck and the orbit. Furthermore the open MRI is useful in the surgery of paranasal sinuses, in the evaluation of tissue-resection and helpful in detection of the anatomy of delicate structures as the internal carotid artery, the skull-base and the orbit. Also navigation in open MRI is possible for example with a flash-point-system. The advantage to conventional navigation systems is the possibility of real-time-imaging, which allows detection of tissue shift occurring during the procedure. We report about our experience with ten biopsies of the petrous apex and the petroclival junction and two biopsy of the parapharyngeal space and the neck. Further experience was gained with MR guided placement of afterloading tubes into large neck metastases in three cases and microscopic surgery of paranasal sinuses in five cases. In all operative procedures an excellent resolution was found especially for soft tissue structures as for example blood vessels. With the aid of special pointer systems or artefacts by surgical instruments all relevant anatomical structures could be detected intraoperatively, concerning normal and pathologic tissue. Thus open MRI proved to be a helpful instrument in these operative procedures.

Marrow-mindedness: a perspective on neuropoiesis

There are pluripotent stem cells in the adult brain that might not be very different from those found in bone marrow. Recent and profound advances in the field of neuropoiesis, which often rely on insights from studies of hematopoiesis and in some instances use cross-paradigms with this field, have already revealed that bone marrow has much in common with so-called 'brain marrow'. Proliferative primogenitors and developmentally regulated molecules are hallmarks of both neuropoiesis and hematopoiesis. This article will focus on recent advances in neuropoiesis within a central core of the mature brain that is referred to as brain marrow, discussing its pluripotency and proliferative capacity, in vitro and molecular assays used in its study, and markers of neuropoietic stem/progenitor cells. As hematopoiesis research has led to the discovery of numerous morphogenetic factors, it is anticipated that studies of neuropoiesis should also uncover many new factors and genes that affect the growth and differentiation of neural cells. Recent breakthroughs in the stem-cell field prompt an inclusion of rationale for the persistence of normal stem/progenitor cells even in the aged brain. By analogy with hematopoiesis research, a thorough investigation of brain marrow should provide basic insights into developmental and persistent neurogenesis while anticipating cell-transplant and gene therapies for debilitating neurological diseases.

Multipotent stem/progenitor cells with similar properties arise from two neurogenic regions of adult human brain

Recent in vitro studies have shown that the periventricular subependymal zone (SEZ) of the rodent brain is capable of de novo generation of neurons and glia. There is less information available on neurogenesis in the adult human brain, and no study has shown the clonal generation of neurons and glia from in vitro-generated "neurospheres." Here we describe the isolation of proliferative stem/progenitor cells within neurospheres from two different regions, the SEZ and the hippocampus, from surgical biopsy specimens of adult (24-57 years) human brain. Using light and electron microscopy; immunocytochemistry for a variety of neuronal, glial, and developmental (including extracellular matrix; ECM) markers; and the reverse transcriptase polymerase chain reaction to demonstrate different gene transcripts found in neurospheres, it is shown that the adult human brain harbors a complex population of stem/progenitor cells that can generate neuronal and glial progeny under particular in vitro growth conditions. These methods also show that these neurospheres contain both neurons and glia and demonstrate regional similarities at the mRNA level, indicating common stem/progenitor cell types within two different neurogenic regions of the adult human brain. In addition to the synthesis of developmentally regulated molecules such as the ECM protein tenascin-C, a variety of other genes (e.g., Pax 6) and proteins (e.g. , Bcl-2) involved in cell survival and differentiation are expressed by adult human brain neurospheres.

[Inverted papilloma of the nose and paranasal sinuses--diagnosis, surgical procedure and studies of cytokeratin profile]

BACKGROUND

Inverted papilloma is a benign sinunasal tumor, characterized by aggressive nature and tendency to recur. This tumor also has a significant malignant potential (10%). In spite of extensive research in the past the origin of inverted papilloma is not known.

METHODS

A retrospective analysis of the clinical data of 28 patients suffering from inverted papilloma of the nose and paranasal sinuses with regard to symptoms, clinical examination, computed tomography findings, and operative management was performed. Furthermore, immunohistochemical examinations of the cytokeratin profile of 12 specimens were carried out.

RESULTS

The most presenting symptoms were unilateral nasal obstruction (17.61%) and rhinorrhea (7.25%). Polyposis was seen endoscopically in 19 cases (68%), so that in many patients in inverted papilloma became suspicious in the CT scan. The surgical therapy was dictated by the extent of the tumor, so that the tumor was treated by lateral rhinotomy (n = 17), midfacial degloving (n = 5), endonasal endoscopic surgery (n = 5), and craniofacial resection due to an infiltration of the frontal skull base (n = 1). An immunohistochemical analysis of the cytokeratin profile revealed for the first time that the inverted papilloma, when compared to the normal surface epithelium of the nasal cavity and the paranasal sinuses, exhibits increased expression of cytokeratin 5, typical for basal cells, and cytokeratin 13, typical for squamous epithelial cells.

CONCLUSIONS

Based on our results we recommend that the endonasal approach is reliable for processes restricted to the middle nasal meatus and the anterior and middle ethmoid cells. Inverted papilloma of the frontal sinus, retrobulbar and supraorbital ethmoid cells, and laterocaudal parts of the maxillary sinus should be resected via lateral rhinotomy or midfacial degloving. The findings of immunohistochemical examinations suggest that inverted papilloma is derived from a cytokeratin 5-immunoreactive cell of the basal layer of the mucosa.

Hippocampal loss of tenascin boundaries in Ammon's horn sclerosis

Ammon's horn sclerosis (AHS) is a common finding in patients with temporal lobe epilepsy (TLE). In addition to selective neuronal cell loss and axonal reorganization, AHS is also characterized by a striking astroglial reaction. However, the functional significance of reactive astrogliosis in the pathogenesis of TLE remains to be determined. Reactive astrocytes produce a variety of cell adhesion molecules and other extracellular matrix (ECM) components with potential effects on axonal growth, axonal branching, and neosynaptogenesis in the central nervous system (CNS). In the present study we describe the distribution of the ECM glycoprotein tenascin/cytotactin (TN-C) in 44 human hippocampal specimens from patients with TLE. The distribution of TN-C immunoreactivity was evaluated with the anti-human TN-C monoclonal antibody K8 by densitometrical analysis, and TN-C protein levels were detected by immunoblotting. In the normal human hippocampus, there were distinctive boundaries between areas of high and low TN-C expression. These border zones demarcated areas with major synaptic input, i.e., the dentate gyrus molecular layer (DG-ML) and the gray matter of the Ammon's horn. TN-C and the neurite growth-associated protein GAP-43 exhibited a complementary pattern of distribution. Densitometric and protein biochemical analysis showed a significant, 4.3-fold increase of TN-C in the hippocampus of TLE patients with AHS compared with normal hippocampus obtained at autopsy. This increase in TN-C immunoreactivity was accompanied by a loss of TN-C boundaries and closely correlated with the extent of reactive gliosis, as indicated by immunoreactivity for glial fibrillary acidic protein. Furthermore, a striking colocalization between TN-C and GAP-43 was observed in the DG-ML of patients with AHS. These observations raise the intriguing possibility of pathogenetically relevant glio-neuronal interactions in human TLE.

Altered distribution of the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor subunit GluR2(4) and the N-methyl-D-aspartate receptor subunit NMDAR1 in the hippocampus of patients with temporal lobe epilepsy

In patients with therapy-refractory temporal lobe epilepsy (TLE), alterations of glutamate receptors have been proposed as a mechanism for enhanced excitability. Using commercially available monoclonal antibodies specific for the N-methyl-D-aspartate (NMDA) receptor subunit NMDAR1 and for the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor subunit GluR2(4), we have examined the distribution of these polypeptides in human hippocampal tissue that was surgically removed from patients with intractable TLE. Surgical specimens were classified according to the presence of Ammon's horn sclerosis (AHS) or a focal lesion in the temporal lobe. Cell counts and a densitometric analysis of the immunoreactivity patterns were carried out for all hippocampal subfields. NMDAR1 and GluR2(4) levels were markedly reduced in patients with AHS, primarily in those subfields with substantial neuronal cell loss (in particular CA1, CA4 and CA3), compared to those seen in patients with focal lesions and in control specimens obtained at autopsy. In contrast, the molecular layer of the dentate gyrus (DG-ML) showed significantly higher levels of GluR2(4) immunoreactivity in AHS compared to control tissue, while NMDAR1 showed no significant up-regulation in this sublayer. When the receptor staining intensity was normalized for alterations in neuronal density, no significant alterations could be detected except for an increase in GluR2(4) in the DG-ML of patients with AHS. These changes may reflect synaptic reorganization observed in the DG-ML of specimens from patients with chronic intractable TLE.

Chalcone synthase in rice (Oryza sativa L.): detection of the CHS protein in seedlings and molecular mapping of the chs locus

The chalcone synthase is a key enzyme that catalyses the first dedicated reaction of the flavonoid pathway in higher plants. The chs gene and its protein product in rice has been investigated. The presence of a chalcone synthase (CHS) protein in rice seedlings and its developmental stage-specific expression has been demonstrated by western analysis. The chalcone synthase of rice was found to be immunologically similar to that of maize. A rice cDNA clone, Os-chs cDNA, encoding chalcone synthase, isolated from a leaf cDNA library of an indica rice variety Purpleputtu has been mapped to the centromeric region of chromosome 11 of rice. It was mapped between RFLP markers RG2 and RG103. RG2 is the nearest RFLP marker located at a genetic distance of 3.3 cM. Some segments of chromosome 11 of rice including chs locus are conserved on chromosome 4 of maize. The markers, including chs locus on chromosome 11 of rice are located, though not in the same order, on chromosome 4 of maize. Genetic analysis of purple pigmentation in two rice lines, Abhaya and Shyamala, used in the present mapping studies, indicated the involvement of three genes, one of which has been identified as a dominant inhibitor of leaf pigmentation. The Os-chs cDNA shows extensive sequence homology, both for DNA and protein (deduced), to that of maize, barley and also to different monocots and dicots.

Preservation of calretinin-immunoreactive neurons in the hippocampus of epilepsy patients with Ammon's horn sclerosis

Selective neuronal vulnerability and aberrant axonal reorganization in the hippocampus may play an important role for the pathogenesis of pharmaco-resistant temporal lobe epilepsy (TLE). Interneurons containing calcium-binding proteins (CaBPs) are candidates for pathogenetically relevant neurons in the hippocampus of patients with TLE. Here we have examined the cellular localization and distribution of calretinin (CR), a recently discovered CaBP, in the hippocampus of 35 patients with TLE. There was a striking preservation of CR-immunoreactive neurons in TLE patients with Ammon's horn sclerosis (AHS). No significant differences in the distribution of CR-immunoreactive neurons were observed between patients with lesion-associated TLE and control patients without epilepsy. However, a subpopulation of CR-immunoreactive interneurons with morphological features of Cajal-Retzius-like cells, which are only transiently detectable in the normally developing hippocampus, was markedly increased in epilepsy patients with AHS. This increase did not correlate with the duration of the epileptic disorder. Another significant finding was a striking increase and reorganization of CR-immunoreactive neuropil throughout the entire molecular layer of the dentate gyrus (DG-ML) in patients with AHS as compared to patients with focal lesions and control specimens. Ultrastructural analysis identified the CR-immunoreactive axonal profiles as components of an inhibitory, intrinsic neuronal system. The presence of a CR-positive, aberrant cell population, in combination with sprouting of CR-positive axonal processes may significantly alter the gating function of the dentate gyrus and thereby increase hippocampal epileptogenicity in epilepsy patients with AHS.

Molecular analysis of C1 alleles in Zea mays defines regions involved in the expression of this regulatory gene

The structure and function of several C1 alleles have been investigated molecularly and the importance of C1 promoter sequences for gene expression was studied using transient transformation assays. The C1 mutants analyzed were the overexpressing allele C1-S, the light-inducible allele c1-p, the null recessive allele c1-n, and the Ds element-induced allele c1-m1. Nucleotide sequence analysis of the alleles revealed a number of differences, predominantly located at the 3' end of the gene. The promoter sequences of the C1 alleles investigated so far (including wild-type and the dominant inhibitor C1-I allele) are almost identical except for two short footprint-like sequences (Box I and Box II) close to the putative CAAT box. Northern blot experiments and transient expression in particle gun experiments indicate that these sequences may be correlated with the different expression patterns of the alleles in the aleurone of maturing and germinating kernels.

Autocatalytic activity of the tobacco etch virus NIa proteinase in viral and foreign protein sequences

The small nuclear inclusion (NIa) protein of the tobacco etch virus (TEV) is synthesized initially as part of a genome-derived high M(r) precursor. The NIa protein releases itself from this genome-derived precursor by self-cleavage, or an autocatalytic processing event. Cleavage between specific glutamine-glycine dipeptides at the N and C termini generates the 430 amino acid or 49,000 M(r) (49K) NIa protein. The requirements of this autocatalytic release, or cis cleavage, were examined by constructing gene cassettes encoding the TEV NIa protein which could be ligated into particular locations in cDNA of the TEV genome and also into foreign gene DNA sequences. Using cell-free transcription and translation systems, polyproteins containing TEV NIa sequences were synthesized and assayed for (i) autocatalysis and (ii) the ability of a functional NIa proteinase, purified from plant tissue, to cleave in bimolecular or trans reactions various artificial polyproteins which contained an inactive form of the NIa proteinase. The NIa self-cleavage events required an active proteinase sequence and a consensus TEV cleavage site sequence at the N and C termini. These results were consistent for NIa protein sequences placed at a foreign TEV cleavage site or in unrelated proteins. Differences were noted in the trans cleavage of these sites.

Interim analysis of a randomized trial of radiation therapy of rectal cancer with/without WR-2721

The objectives of this randomized trial are to define the maximum tolerated dose of radiation therapy, at curative dose levels, that can be delivered following WR-2721, and to observe the anti-tumor effects and normal tissue responses. One hundred patients with inoperable, unresectable, or recurrent rectal cancer were stratified and randomized to radiation only, or WR-2721 and radiation. The entire pelvis is treated with 4 portals 4 times a week to a total of 4500 cGy (first level dose) in 5 weeks. WR-2721, 340 mg/m2 was given 15 minutes before radiation to the combination group. Subsequently, both groups received a conedown of 720 cGy in 4 days to 144(2) cm portals APPA, and if originally inoperable or unresectable 720 cGy in four days to second conedown of 64(2) cm. Patients were observed from 3 to 18 months (median = 12 months). No significant hypotension or hematologic toxicity occurred in the WR-2721 treated group. Mild to moderate emesis occurred in 80% of the courses. (No antiemetics were used.) Moderate or severe acute toxicities to normal tissues were observed less frequently in the WR-2721 arm. No moderate or severe late toxicities to the skin, mucous membrane, urinary bladder or intestine was observed in the WR-2721 group, however, 5 patients treated with radiation alone experienced moderate or severe late toxicity to these organs. No evidence of tumor protection was observed.

The role of hexamethylmelamine in the management of ovarian cancer

Hexamethylmelamine has been recognized as having useful single-agent activity for the treatment of ovarian cancer for the past 25 years, with some patients surviving disease-free for periods in excess of 12 years. Data from recently analysed and mature trials demonstrate that the addition of hexamethylmelamine to first-line combination chemotherapy results in significant improvements in survival compared to what is achieved with regimens of cisplatin and cyclophosphamide with or without doxorubicin.

Analysis of prognostic factors and survival in patients with ovarian cancer treated with second-line hexamethylmelamine (altretamine)

Hexamethylmelamine (altretamine, HMM) 260 mg/m2/day p.o. for 14 days followed by a 14-day drug-free interval was administered to 52 outpatients with advanced ovarian cancer who had previously been treated with chemotherapy. Prior to HMM, 92% (48/52) of these patients had received cisplatin and cyclophosphamide with or without doxorubicin. Two more patients received other cisplatin-based regimens. At the completion of HMM therapy, 15% (8/52) displayed no evidence of disease (NED). Of these eight patients, five are still alive 32 to 82 months after altretamine therapy (median follow-up of 46 months). At 41 months, one patient died of intercurrent illness with no clinical evidence of recurrence; the other two patients died of their disease at 21 and 31 months following HMM therapy. The median survival of the total group was 11 months: nine months for patients who did not respond to altretamine and 46+ months for patients with NED after altretamine (p less than 0.05). Intermittent oral administration of single-agent altretamine was well tolerated: eight patients reported moderate gastrointestinal symptoms, and only one patient reported severe gastrointestinal symptoms. Moderate neurologic toxicity was reported by five patients. No WBC fell below 2000 mm3 and platelet counts fell below 100,000 mm3 in only three patients; no patient experienced severe hematologic toxicity. In this series of patients, the overall response (15%) was comparable to or better than those reported for more toxic chemotherapeutic regimens. On the basis of these data and those reported by other investigators, HMM warrants consideration as a reasonable option in the management of recurrent or persistent ovarian cancer.

Hexamethylmelamine as a single second-line agent in ovarian cancer

Fifty-two patients with advanced ovarian cancer were treated with single-agent hexamethylmelamine (HMM), 260 mg/m2 po per day for 14 days followed by 14 days off drug. All patients had been previously treated with chemotherapy. Of these patients, 92% (48/52) received cisplatin and cyclophosphamide +/- doxorubicin prior to hexamethylmelamine. Two additional patients received other cisplatin-based regimens. Fifteen percent (8/52) were found to have no evidence of disease (NED) at the completion of treatment with HMM. Five of these patients are alive at 12 to 65 months (median follow-up of 32 months); one patient died at 41 months of an intercurrent illness with no clinical evidence of recurrence; two patients died of recurrent tumor at 21 and 31 months. The median survival of the series of 52 patients is 11 months: 9 months for patients who did not respond versus 41 months for patients with NED post-HMM (P less than 0.05). The regimen was well tolerated: moderate gastrointestinal toxicity was reported by 8 patients; only one patient reported severe gastrointestinal toxicity. Moderate neurologic toxicity (primarily sensory) was reported by 5 patients, 3 patients experienced white counts less than 2000 or platelet counts less than 100,000, and no patient sustained severe hematologic toxicity. This moderate-dose intermittent regimen was associated with moderate toxicity and was well accepted by patients. The overall response is comparable to or higher than that reported for more toxic chemotherapy regimes. Based on these data and those recently reported by other authors, hexamethylmelamine should be considered in the treatment of recurrent ovarian cancer.