Patterns of failure after brain metastases radiotherapy: reflections on the importance for treatment and clinical trials reporting.

In many ongoing clinical trials, new strategies for radiotherapy of brain metastases are currently being investigated. A post surgical focal cavity stereotactic radiosurgery and the developing role of a hippocampal-sparing whole brain radiotherapy are of the highest importance. The evaluation of spatial patterns of metastases failure after radiotherapy is a powerful tool for assessing the potential benefit of new different radiotherapy approaches, which enables to identify possible directions leading to better radiotherapy techniques and to modify general management for newly diagnosed brain metastases. The purpose of this article is to present a mix between trial data and philosophical point of view for discussion about the importance of systematic evaluation of spatial patterns of failure in all ongoing trials investigating new approaches in local brain metastases treatment.

[Controversy in the Postoperative Treatment of Low-grade Gliomas]. / Kontroverze v pooperacní lécbe low-grade gliomu.

BACKGROUND: The optimal treatment for low-grade gliomas remains controversial. Neurosurgery, radiotherapy, and chemotherapy are the main treatment options. Despite advances in oncology, there are still a lot of uncertainties, and the optimal sequences, combinations, and timings of these procedures have not yet been optimized. It is still unclear whether temozolomide can replace effective, but toxic PCV chemotherapy (procarbazine, lomustine, vincristine) and whether temozolomide can be used upfront alone instead of radiotherapy alone. Mature results from phase III trials (CODEL, EORTC 22033-26033) will provide answers to these questions. Correlative analyses of survival data and molecular marker findings (1p/19q codeletion, IDH1/2 mutation, and MGMT promoter methylation status) are essential. Due to slow progressive nature of the disease, all clinical trials with low-grade gliomas are complicated by the need for long-term follow-up to obtain valid mature data, which makes any new treatment procedures or developments in basic research developed during the course of closed clinical trials difficult to apply in daily clinical practice. An example is the recently published RTOG 9802 study evaluating the role of adjuvant PCV in combination with radiotherapy for the treatment of high-risk low-grade glioma patients where the recruitment of patients was initiated almost two decades ago. Health-related quality of life after treatment of patients with expected long-term survival is also very important and its maintenance is currently the focus of considerable interest. AIM: The main objective of the present review is to summarize the results of key clinical trials and highlight controversial issues that could have an impact on future daily practice. Another aim is to discuss these issues in the light of newly established molecular markers from the new 2016 WHO Classification of Tumors of the Central Nervous System.Key words: glioma - astrocytoma - radiotherapy - temozolomide - PCV - cognition This work was supported by MH CZ - RVO (MMCI, 00209805) and by project of the Ministry of Education, Youths and Sports of the Czech Republic CEITEC 2020 (LQ1601). The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 21. 2. 2017Accepted: 20. 3. 2017.

[The Role of Chemotherapy in the Treatment of Low-grade Gliomas]. / Postavení chemoterapie v pooperacní lécbe low-grade gliomu.

BACKGROUND: The standard postsurgical options for low-grade gliomas include watchful waiting or radiotherapy depending on the risk factors for recurrence. The use of chemotherapy for the treatment of this disease is generally controversial, although the recently published results of the first of two large randomized phase III clinical trials (RTOG 9802 a EORTC 22033-26033), focusing on the evaluation of chemotherapy for the upfront treatment of newly diagnosed low-grade gliomas, are reassuring in this respect. The long-term results of a RTOG 9802 comparing radiotherapy alone with radiotherapy and six cycles of adjuvant PCV chemotherapy (procarbazine, lomustine, vincristine) in patients with high-risk low-grade gliomas will probably have an impact on daily clinical practice. The increase in median overall survival from 7.8 years to 13.3 years, mainly for patients with oligodendrogliomas, is unprecedented, but the toxicity of PCV is too high and molecular marker analysis remains inadequate. It is still unclear whether less toxic temozolomide can replace PCV and whether temozolomide can be used upfront alone instead of with radiotherapy. This question is addressed by the ongoing EORTC 22033-26033 study. The preliminary results show no significant difference in progression-free survival between patients receiving radiotherapy and those receiving temozolomide alone. Treatment with temozolomide was not associated with an improvement in cognitive function compared with treatment with radiotherapy. Despite limited follow-up, the study clearly confirmed the importance of molecular characterization of low-grade gliomas, as currently defined in the new 2016 WHO Classification of Tumors of the Central Nervous System. AIM: The aim of the review is to summarize available information from listed key clinical trials of chemotherapy for low-grade gliomas and draw attention to unresolved issues concerning the use of chemotherapy for the treatment of this disease.Key words: glioma - astrocytoma - chemotherapy - PCV - temozolomide - RTOG 9802 This work was supported by MH CZ - RVO (MMCI, 00209805) and by project of the Ministry of Education, Youths and Sports of the Czech Republic CEITEC 2020 (LQ1601). The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 21. 2. 2017Accepted: 20. 3. 2017.

[The Impact of Corticotherapy on the Diagnostic Yield of Stereotactic Biopsy in Patients with Brain Lymphoma]. / Vliv kortikoterapie na diagnostickou výteznost stereotaktické biopsie u nemocných s lymfomem mozku.

Backround: Because of the dismal prognosis of untreated brain lymphoma early histological verification using stereobiopsy is decisive for patient with this disease. The study analysed the diagnostic yield of stereobiopsy in brain lymphoma patients with respect to prebiopsy corticosteroid administration. PATIENTS AND METHODS: Patients with brain lymphomas were identified in a group of 162 stereotactic biopsies (108 frame-based and 54 frameless) of patients harboring suspected brain tumor. Non conclusive biopsies were reevaluated to exclude the possibility of missed lymphoma. RESULTS: Total 9 patients (8.3%) and 4 patients (7.4%) had lymphomas in the frame-based and frameless stereobiopsy groups, resp. In 10 patients, corticosteroid treatment of perifocal brain oedema was conducted continually up until biopsy (including one patient with corticotherapy for pulmonary disease). Lesion regression was observed in 6 of these patients. Transient lesion remission was observed during corticotherapy in one patient with lesion recurrence after steroid discontinuation. In 2 patients, corticosteroids were not administered before biopsy. The results of stereobiopsy were inconclusive in 8 patients (4.9%). Before biopsy, the possibility of brain lymphoma was considered in 3 patients, but the final diagnoses were autoimmune vasculitis, histological changes after embolic events from the thrombosed pulmonary veins in pulmonary malformation and local inflammation. CONCLUSION: Although the extent of brain lymphoma decreased after corticosteroid administration, corticotherapy does not exclude valid diagnostic biopsy.Key words: brain lymphoma - stereotaxic techniques - frameless stereotaxy - stereotactic biopsy - corticosreroids Part of the message was presented on XLI. Brno Oncological Days within the Glio Meeting and published in the form of a short abstract. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 27. 5. 2017Accepted: 2. 7. 2017.

Utilization of Prognostic Indexes for Patients with Brain Metastases in Daily Radiotherapy Routine -  is the Complexity and Intricacy Still an Issue?

BACKGROUND: Many prognostic indexes are available for patients with brain metastases in order to estimate remaining lifetime before selection of appropriate treatment including palliative radiotherapy. Their routine utilization is often deprecated for their complexity. We developed a practical tool based on widely available spreadsheet editors for facilitation of daily clinical use of selected indexes (RPA, GPA and WBRT 30) and evaluated its usage for retrospective single institutional survival analysis of patients irradiated for brain metastases. PATIENTS AND METHODS: Spreadsheet platform was prepared and adjusted for automatic calculation of selected prognostic indexes after input of the relevant parameters. The consecutive series of newly diagnosed patients referred during 2011 to the palliative brain radiotherapy were analyzed, and real calculated survival parameters of individual subgroups of RPA, GPA and WBRT 30 were compared with estimated ones. Correlation of radiotherapy technique and estimated survival at the time of treatment indication was evaluated. RESULTS: Total of 121 patients (61% with multiple metastases) were irradiated with the majority undergoing whole brain radiotherapy. Median overall survival from the time of radiotherapy indication was 3.13 months. Non balanced distribution into individual scoring systems subgroups was observed with 8 (7%), 89 (73%) and 24 (20%) patients assigned to RPA 1, 2 and 3 subgroup, 3 (3%), 9 (7%), 57 (47%) and 52 (43%) patients assigned to GPA 3.5- 4, GPA 3.0, GPA 1.5- 2.5 and GPA 0- 1.0 subgroup and 10 (8%), 88 (73%) and 23 (19%) patients assigned to WBRT 30 subgroup D, B and A. Entire differences in overall survival between subgroups are significant among all three scoring systems. CONCLUSION: Routine calculation of available prognostic indexes is useful in decision making regarding the best radiotherapy of brain metastases, and their calculation is greatly facilitated by properly prepared widely available spreadsheet tools.

[Neuroendoscopic biopsy of a brain tumor]. / Neuroendoskopická biopsie tumoru mozku.

BACKGROUNDS: Neuroendoscopic biopsy is one of the techniques that can be used for histological verification of a suspected brain tumor. The use of neuroendoscopy is particularly useful for cystic tumors and para- and intraventricular brain tumors that are risky for stereotactic biopsy. The technique of navigated neuroendoscopy enables biopsy sampling under visual control, haemostasis of biopsy site and treatment of cerebrospinal fluid pathways obstruction. PATIENTS AND METHODS: Neuroendoscopic technique was used for biopsy in one patient with a solid brain tumor. 23 patients (12 males, mean age 49.7 years, range 21-75 years and 11 females, mean age 59.1 years, range 22-76 years) with a suspected cystic brain tumor underwent neuroendoscopic biopsy. Suspected intra- or paraventricular brain tumor presented indication for neuroendoscopic biopsy in 36 patients (20 males, mean age 43.9 years, range 6-80 years and 16 females, mean age 46.2 years, range 11-78 years). RESULTS: High grade glioma was most frequently diagnosed in patients with cystic brain tumors, followed by low grade gliomas and metastatic tumors. Diagnostic sample was obtained from all patients. Tumor resection was performed in 7 patients with a cystic tumor after neuroendoscopic biopsy and histological findings were identical in 70.1% of them. Similarly, high grade glioma was most frequently diagnosed in patients with intra or paraventricular tumors, followed by tumors originating from pineal region tissues. Diagnostic sample was obtained from 94.3% of patients. Tumor resection was performed in 5 patients after neuroendoscopic biopsy and histological findings of the resected tissue was identical with neuroendoscopic biopsy in 4 of them (80%). CONCLUSIONS: Neuroendoscopy is a safe biopsy technique for a subset of patients who are high risk for the use of stereotactic biopsy, with comparable results. Neuroendoscopy also provides for cerebrospinal fluid circulation obstruction treatment. The use of neuronavigation or stereotactic planning is particularly useful for the planning of an optimal surgical approach, helps to maintain anatomical orientation in distorted anatomy and facilitates haemostasis in case of intraoperative bleeding.

[Opportunistic infections in patients after complex therapy of cancer]. / Oportunní infekce mozku u pacientu po komplexní terapii nádorového onemocnení.

BACKGROUNDS: An opportunistic infection is an infection caused by pathogens, such as Toxoplasma gondii, that usually are not pathogenic in a healthy host but may cause an infection in immunocompromised patients. Although the most frequent cause of an opportunistic infection is immunodeficiency due to HIV infection, the immunodeficiency induced by anticancer treatment cannot be ignored. DESIGN: A 56-year old female patient after a comprehensive treatment of breast cancer underwent a stereotactic biopsy of MR-verified multiple brain lesions suspected to be of metastatic aetiology. The histology report unexpectedly concluded that the lesion was brain toxoplasmosis confirmed by detection of IgM specific antibody in cerebrospinal fluid. Immunology examination has proven a deficit of cell-mediated immunity. The symptoms (cephalea, cerebellar symptomatology with vertigo) and MR findings disappeared following 6-month treatment with a combination of pyrimethamin, sulfadiazin and leucovorin. CONCLUSION: Since neoplastic duplicities and brain lesions of non-neoplastic aetiology are found in about 11% of oncology patients, histological verification of aetiology of intracranial lesions is essential for targeted therapy of these patients. Our case of brain toxoplasmosis documents the role of opportunistic infections in differential diagnosis of brain lesions in patients who underwent anticancer treatment.

[Distant wounded glioma syndrome following stereotactic biopsy--a case review]. / Vzdálený syndrom zraneného gliomu po stereotaktické biopsii--kazuistika.

Postoperative haemorrhage is a threatening complication of both brain tumor resection and stereotactic biopsy. The paper describes rare case report of distant wounded glioma syndrome after stereotactic biopsy of glioblastoma, when small distant bleeding was proven in the tumor nodule distant from the original site of biopsy.

[New therapeutic options in therapy of glioblastoma multiforme]. / Nové moznosti I lécby glioblastoma multiforme.

Glioblastoma multiforme is one of the most aggressive malignant brain tumours with limited therapeutics options. Standard therapy is maximal surgical resection and adjuvant concurrent chemo-radiotherapy and maintenance therapy with temozolomide. This approach improves median and 5-year survival in comparison with postsurgical radiotherapy alone. Additional predictive and prognostic biomarkers are necessary, especially due to the development of targeted therapy--antibodies and tyrosine kinase inhibitors. These new therapeutic approaches are under intensive investigation. The most promising data currently available are for anti-angiogenic therapies, such as bevacizumab and cediranib. This review presents a summary of the possible role of targeted therapy in the treatment of glioblastoma multiforme.

Integrated dia-gnostics of diffuse gliomas.

Recently, the World Health Organization (WHO) classification of tumours of the central nervous system (CNS) has brought essential changes. The currently valid revised WHO 2016 classification of CNS tumours introduced the concept of integrated dia-gnostics, which incorporated not only histopathological morphological finding and immunophenotype but also molecular-genetic characteristics of the tumour. Thus, the final integrated dia-gnosis comprises the traditional morphological and growth pattern characteristics of a tumour including histopathological grade and also specific molecular bio-markers. The classification of tumour based on a combination of both tumour phenotype and genotype enables more precise prognostic stratification, increases the objectivity of dia-gnostics and prediction of response to treatment. In 2017, an international platform, The Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy - not official WHO (cIMPACT-NOW), was established to create and formulate practical recommendations for integrated dia-gnostics of CNS tumours and upcoming WHO classification. The incorporation of molecular bio-markers into the integrated dia-gnostics radically changed the classification of diffuse gliomas, which include entities with different morphological characteristics, genetic alterations and bio-logical behaviour. This review article summarizes essential morphological, immunophenotypical and molecular genetic characteristics of diffuse gliomas within the scope of integrated dia-gnostics according to the valid WHO classification of tumours of the CNS and subsequent recommendations of dia-gnostic approaches. This work was supported by grant of the Ministry of Health of the Czech Republic - Conceptual Development of a Research Organization (MMCI 00209805) and Grant Agency of Masaryk University (MUNI/A/1562/2018). The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.

Increased invasion of ED-1 positive macrophages in both ipsi- and contralateral dorsal root ganglia following unilateral nerve injuries.

There is an increasing evidence that unilateral nerve injury induces cellular and molecular changes in the associated DRG not only on the ipsilateral but also in the contralateral side. In this investigation, ED-1+ macrophages were quantified by image analysis in the naïve L5 DRG (nDRG) and compared with the ipsi- and contralateral ones 2 and 4 weeks after unilateral sciatic nerve ligature and ventral root transection (VRT). A few ED-1+ macrophages were found in nDRG but not closely associated with the neuronal bodies. In contrast, following nerve injuries ED-1+ macrophages and their processes were frequently located close neuronal bodies and became their satellite cells. Moreover, an increased number of ED-1+ cells was found in the ipsilateral DRG 2 weeks after unilateral sciatic nerve ligature or VRT, but no significant differences were measured between 2 and 4 weeks after both types of nerve lesion. Contralateral DRG displayed a significant enhanced number of ED-1+ cells no sooner than 4 weeks from sciatic nerve ligature. In contrast, VRT induced a significant increased invasion of the ED-1+ cells in the contralateral DRG as early as 2 weeks after operation. Our experiments indicate that a significantly higher number of ED-1+ macrophages remained in both ipsi- and contralateral DRG up to 4 weeks from nerve injury. Based on results from different models of nerve injury, we suggest that more than one mechanism operates to stimulate the invasion of ED-1+ macrophages into the DRG including retrograde transport of factors produced during Wallerian degeneration or their delivery by blood flow. Signaling for macrophage invasion into DRG contralateral to nerve injury may be mediated by lost motoneurons or by interneurones.

Volumetric modulated arc therapy for hippocampal-sparing radiotherapy in transformed low-grade glioma: A treatment planning case report.

Timing of radiotherapy for low-grade gliomas is still controversial due to concerns of possible adverse late effects. Prevention of possible late cognitive sequelae by hippocampal avoidance has shown promise in phase II trials. A patient with progressive low-grade glioma with gradual dedifferentiation into anaplastic astrocytoma is presented along with description of radiotherapy planning process attempting to spare the hippocampus. To our knowledge, this is the first described case using volumetric modulated arc technique to spare hippocampus during transformed low-grade glioma radiotherapy. Using modern intensity-modulated radiotherapy systems it is possible to selectively spare hippocampus together with other standard organs at risk. For selected patients, an attempt to spare hippocampus can be considered as long as other dose characteristics are not significantly compromised compared to standard treatment plan created without any effort to avoid hippocampus.

Immunohistochemical localization of some extracellular molecules and their integrin receptors in the rat Pacinian corpuscles.

The present results suggest that laminin-1 and 3 are localized in the specialized Schwann cells of Pacinian corpuscles, in spite of incomplete deposition of the basal lamina on the surface of their cytoplasmic processes. In addition, laminin-3 is concentrated and probably function as a stop protein not only in the neuromuscular junction, but also in the specialized Schwann cells enveloping the dendritic zone of the afferent axon. No significant changes of immunostaining for both laminins and their integrin receptors following denervation of Pacinian corpuscles indicate that their synthesis is independent to afferent axon as a prerequisite for successful reinnervation.

Immunohistochemical localization of laminin-1 in the acellular nerve grafts is associated with migrating Schwann cells which display corresponding integrin receptors.

The presence of laminin-1, collagen-IV, alpha6 and beta1 integrin chains was detected by indirect immunohistochemistry using biotin/streptavidin/HRP or gold-conjugated secondary antibody at the light and electron microscope level, respectively. Cryo-treated segment of the peripheral stump without living Schwann cells (S-100-) did not display immunoreactivity for laminin-1 and integrin's chains, while the migrating Schwann cells in the marginal regions were immunostained for the antigens. Isolated acellular nerve segments protected from migration of Schwann cells (S-100-) exhibited laminin-1-, beta1-, and alpha6- integrin chains immunoreactivities. Position of the basal lamina was verified by collagen-IV+ immunoreactivity. Results indicate that presence of the laminin in the peripheral nerve is related with living Schwann cells.

Utility of a rescue endovascular therapy for the treatment of major strokes refractory to full-dose intravenous thrombolysis.

OBJECTIVE: Large artery occlusion (LAO) in patients with major stroke predicts poor revascularization by intravenous thrombolysis (IVT) and more likely results in a poor outcome. We focused on the effects of intra-arterial thrombolysis (IAT) and endovascular mechanical recanalization (EMR) as rescue therapies in major strokes refractory to IVT. METHODS: A retrospective analysis of 87 patients (National Institutes of Health Stroke Scale >20), who did not respond to full-dose IVT due to LAO, was performed based on their endovascular therapy status. IAT was performed as an intraclot infusion of alteplase, and EMR was provided by the Solitaire device™ (Covidien, Dubin, Ireland). The recanalization and 3-month outcome rates after IAT/EMR were correlated with a group of patients who were scheduled to receive endovascular treatment but who underwent only IVT. RESULTS: We achieved successful recanalization by IAT and EMR in 68.7% and 76.1% of patients, respectively. Despite no significant differences in mortality between IAT and EMR, a trend towards better outcomes after IAT and a statistically significant increase for outcome-modified Rankin scale (mRS) 0-3 (45.7%) and mRS 0-2 (34.9%) after EMR was noted when compared with IVT. The degree of recanalization did not correlate with the functional results except for the good-moderate outcome after successful recanalization by EMR. CONCLUSION: EMR by the Solitaire device is a safe and beneficial method for the rescue treatment of patients with major stroke whose neurological status does not improve and who fail to recanalize the LAO after a 1-h full dose of IVT. ADVANCES IN KNOWLEDGE: The article verifies efficiency of the Solitaire device in major strokes.

Bilateral changes of IL-10 protein in lumbar and cervical dorsal root ganglia following proximal and distal chronic constriction injury of peripheral nerve.

Interleukin-10 prevents transition of a physiological inflammatory reaction to a pathological state that may result in neuropathic pain. We studied bilateral changes of IL-10 protein levels in L4-L5 and C7-C8 dorsal root ganglia (DRG) after a chronic constriction injury (CCI) of either L4-L5 spinal nerves (pCCI) or the sciatic nerve (dCCI). Rats undergoing pCCI or dCCI were left to survive for 1, 3, 7 or 14 d, sham-operated rats for 3 or 14 d. After the survival time, C7-C8 and L4-L5 DRG were removed bilaterally from naïve, operated, and sham-operated rats and IL-10 protein was detected by immunohistochemical staining and measured using ELISA analysis. Unilateral pCCI and dCCI induced a transient bilateral elevation in IL-10 protein level not only in the homonymous lumbar DRG but also in the heteronymous cervical DRG nonassociated with the spinal segments of constricted nerve. Sham operations also induced bilateral elevation of IL-10 protein in both homonymous and heteronymous DRG. Our experiments revealed that the more proximal is a nerve injury the more rapid is the initial increase and slower the subsequent decrease of IL-10 protein level in DRG. Changes of IL-10 protein in DRG nonassociated with damaged nerve could be related to a general neuroinflammatory reaction of the nervous system to injury and thereby promote potential of the DRG neurons for regenerating their axons following a conditioning lesion.

An experimental animal model of spinal root compression syndrome: an analysis of morphological changes of myelinated axons during compression radiculopathy and after decompression.

The treatment of radicular pain is mainly empirical because there are only few experimental studies dealing with morphological changes during compression radiculopathy. The goal of the study was to investigate changes in the morphology of myelinated axons during spinal root compression and the influence of decompression in a new rat model. The number of myelinated axons and their diameter were measured at 1, 2, 5, and 8 weeks during compression of the dorsal spinal root. The same approach was applied for 1-week compression followed by decompression for 1 or 2 weeks and compression for 5 weeks followed by 3-week decompression. A decrease in the number of myelinated axons (particularly those of large diameters) occurred after compression for 1 week. Continued compression for up to 8 weeks resulted in centripetal increase in the number of myelinated axons and the persistence of a small fraction of large myelinated axons at the site of compression. After that time, a decreased number of axons and a reduced fraction of large myelinated axons occurred again. Decompression after 1-week compression caused a rapid increase in the number of both small and large myelinated axons within the spinal root including the site of compression. A small fraction of regenerated axons was found after 5-week compression followed by 3-week decompression. Finally, we investigated the time course of the temporary increase in the number of regenerated myelinated axons during dorsal root compression for up to 8 weeks. The efficacy of decompression was superior when applied one week after compression or after regress of the acute phase of aseptic inflammation associated with fragility of spinal root. The results of the study verify the need for early surgical decompression to prevent irreversible damage of the spinal roots.

Intra- and extraneuronal changes of immunofluorescence staining for TNF-alpha and TNFR1 in the dorsal root ganglia of rat peripheral neuropathic pain models.

1. Several lines of evidence suggest that cytokines and their receptors are initiators of changes in the activity of dorsal root ganglia (DRG) neurons, but their cellular distribution is still very limited or controversial. Therefore, the goal of present study was to investigate immunohistochemical distribution of TNF-alpha and TNF receptor-1 (TNFR1) proteins in the rat DRG following three types of nerve injury. 2. The unilateral sciatic and spinal nerve ligation as well as the sciatic nerve transection were used to induce changes in the distribution of TNF-alpha and TNFR1 proteins. The TNF-alpha and TNFR1 immunofluorescence was assessed in the L4-L5 DRG affected by nerve injury for 1 and 2 weeks, and compared with the contralateral ones and those removed from naive or sham-operated rats. A part of the sections was incubated for simultaneous immunostaining for TNF-alpha and ED-1. The immunofluorescence brightness was measured by image analysis system (LUCIA-G v4.21) to quantify immunostaining for TNF-alpha and TNFR1 in the naive, ipsi- and contralateral DRG following nerve injury. 3. The ipsilateral L4-L5 DRG and their contralateral counterparts of the rats operated for nerve injury displayed an increased immunofluorescence (IF) for TNF-alpha and TNFR1 when compared with DRG harvested from naive or sham-operated rats. The TNFalpha IF was increased bilaterally in the satellite glial cells (SGC) and contralaterally in the neuronal nuclei following sciatic and spinal nerve ligature. The neuronal bodies and their SGC exhibited bilaterally enhanced IF for TNF-alpha after sciatic nerve transection for 1 and 2 weeks. In addition, the affected DRG were invaded by ED-1 positive macrophages which displayed simultaneously TNFalpha IF. The ED-1 positive macrophages were frequently located near the neuronal bodies to occupy a position of the satellites. 4. The sciatic and spinal nerve ligature resulted in an increased TNFR1 IF in the neuronal bodies of both ipsi- and contralateral DRG. The sciatic nerve ligature for 1 week induced a rise in TNFR1 IF in the contralateral DRG neurons and their SGC to a higher level than in the ipsilateral ones. In contrast, the sciatic nerve ligature for 2 weeks caused a similar increase of TNFR1 IF in the neurons and their SGC of both ipsi- and contralateral DRG. The spinal nerve ligature or sciatic nerve transection resulted in an increased TNFR1 IF located at the surface of the ipsilateral DRG neurons, but dispersed IF in the contralateral ones. In addition, the SGC of the contralateral in contrast to ipsilateral DRG displayed a higher TNFR1 IF. 5. Our results suggest more sources of TNF-alpha protein in the ipsilateral and contralateral DRG following unilateral nerve injury including macrophages, SGC and primary sensory neurons. In addition, the SGC and macrophages, which became to be satellites, are well positioned to regulate activity of the DRG neurons by production of TNF-alpha molecules. Moreover, the different cellular distribution of TNFR1 in the ipsi- and contralateral DRG may reflect different pathways by which TNF-alpha effect on the primary sensory neurons can be mediated following nerve injury.