Toll-like receptor triggered dendritic cell maturation and IL-12 secretion are necessary to overcome T-cell inhibition by glioma-associated TGF-β2

Malignant gliomas are able to secrete large amounts of immunosuppressive cytokines like transforming growth factor beta 2 (TGF-beta2) and regularly escape from immune surveillance. Many strategies have been developed to induce potent anti-glioma responses, among those the use of dendritic cells (DC) as therapeutic vaccines. Here, we report that both mature DC and IL-12 secretion are necessary to overcome T-cell inhibition by TGF-beta2. Flow cytometric analyses showed that TGF-beta2 does not suppress the upregulation of MHC (major histocompatibility complex) class II molecules and the T cell stimulatory capacity of human DC that were stimulated with a strong cytokine cocktail containing tumor necrosis factor alpha (TNF-alpha), IL-1beta, IL-6 and prostaglandin E2 (PGE2). Moreover, TGF-beta2 signaling studies revealed that these cytokine-matured DC become unresponsive to TGF-beta2. Although both mature and immature DC expressed comparable amounts of the TGF-beta receptor type II, Smad2 phosphorylation and subsequent upregulation of Smad7 was inhibited in mature DC, but not immature DC. However, further analysis revealed that mature DC alone are not sufficient to mediate full T cell activation in the presence of TGF-beta2, unless IL-12 is added to the DC/T-cell coculture. Finally, we demonstrate that MHC class II expression and IL-12 secretion by DC are not disturbed by TGF-beta2 after DC stimulation with a modified maturation cocktail containing the Toll-like receptor (TLR)-ligands Poly I:C or R848, TNF-alpha, IL-1beta and INF-gamma. These data imply that mature DC retaining their capacity to produce IL-12 are of favorable use in glioma immunotherapy and suggest that TLR triggering of DC plays an important role to elicit a strong immune response in the immunosuppressive environment of malignant gliomas.

Intracerebral and intrathecal infusion of the TGF-beta 2-specific antisense phosphorothioate oligonucleotide AP 12009 in rabbits and primates: toxicology and safety

Here, we provide first evidence that long-term continuous infusion of highly purified antisense phosphorothioate oligodeoxynucleotides (S-ODN) into brain parenchyma is well tolerated and thus highly suitable for in vivo application. AP 12009 is an S-ODN for the therapy of malignant glioma. It is directed against human transforming growth factor-beta (TGF-beta2) mRNA. In the clinical setting, AP 12009 is administered intratumorally by continuous infusion directly into the brain tumor. In view of this clinical application, the focus of our data is on local toxicology studies in rabbits and monkeys to evaluate the safety of AP 12009. AP 12009 was administered either by intrathecal bolus injection into the subarachnoidal space of the lumbar region of both cynomolgus monkeys and rabbits or by continuous intraparenchymatous infusion directly into the brain tissue of rabbits. Intrathecal bolus administration of 0.1 ml of 500 microM AP 12009 showed neither clinical signs of toxicity nor macroscopically visible or histomorphologic changes. After a 7-day intraparenchymatous continuous infusion of 500 microM AP 12009 at 1 microl/h in rabbits, there was no evidence of toxicity except for local mild to moderate lymphocytic leptomeningoencephalitis. Additionally, AP 12009 showed good tolerability in safety pharmacology as well as in acute toxicity studies and 4-week subchronic toxicity studies in mice, rats, and monkeys. This favorable safety profile proves the suitability of AP 12009 for local administration in brain tumor patients from the point of view of toxicology.

Mesenchymal Stem Cells Instruct Oligodendrogenic Fate Decision on Adult Neural Stem Cells

Adult stem cells reside in different tissues and organs of the adult organism. Among these cells are MSCs that are located in the adult bone marrow and NSCs that exist in the adult central nervous system (CNS). In transplantation experiments, MSCs demonstrated neuroprotective and neuroregenerative effects that were associated with functional improvements. The underlying mechanisms are largely unidentified. Here, we reveal that the interactions between adult MSCs and NSCs, mediated by soluble factors, induce oligodendrogenic fate decision in NSCs at the expense of astrogenesis. This was demonstrated (a) by an increase in the percentage of cells expressing the oligodendrocyte markers GalC and myelin basic protein, (b) by a reduction in the percentage of glial fibrillary acidic protein (GFAP)-expressing cells, and (c) by the expression pattern of cell fate determinants specific for oligodendrogenic differentiation. Thus, it involved enhanced expression of the oligodendrogenic transcription factors Olig1, Olig2, and Nkx2.2 and diminished expression of Id2, an inhibitor of oligodendrogenic differentiation. Results of (a) 5-bromo-2'-deoxyuridine pulse-labeling of cells, (b) cell fate analysis, and (c) cell death/survival analysis suggested an inductive mechanism and excluded a selection process. A candidate factor screen excluded a number of growth factors, cytokines, and neurotrophins that have previously been shown to influence neurogenesis and neural differentiation from the oligodendrogenic activity derived from the MSCs. This work might have major implications for the development of future transplantation strategies for the treatment of degenerative diseases in the CNS.

Thin corpus callosum and amyotrophy in spastic paraplegia—Case report and review of literature

We report the clinical, structural, functional and genetic characterization of a 37-year-old Caucasian female, presenting as a sporadic case of complicated spastic paraplegia with thin corpus callosum (CC), cognitive impairment, amyotrophy of the hand muscles and a sensorimotor neuropathy and review the literature for spastic paraplegia with thin CC. Magnetic resonance imaging (MRI) examination revealed a thin CC with fronto-parietal cortical atrophy. 18Fluordesoxyglucose positron emission tomography (FDG-PET) showed reduced cortical and thalamic metabolism. By transcranial magnetic stimulation, we delineated a severe impairment of transcallosal inhibition. Sequence analysis did not reveal disease causing mutations in the genes SLC12A6 (Andermann), Spastin (SPG 4), BSCL2 (SPG 17) and Spartin (SPG 20). We reviewed the literature for HSP with thin CC and found 113 HSP patients with thin CC previously described (35 with linkage to chromosome 15q13-15). Thin CC and peripheral neuropathy often appear together in spastic paraplegia and might be indicative for combined degeneration mechanism of central and peripheral axons.

Effects of the implementation of a telemedical stroke network: the Telemedic Pilot Project for Integrative Stroke Care (TEMPiS) in Bavaria, Germany

BACKGROUND

Telemedical networks are a new approach to improve stroke care in community settings. We aimed to assess the effects of a stroke network with telemedical support in Germany on quality of care, according to acute processes and long-term outcome.

METHODS

Five community hospitals without pre-existing specialised stroke care were included in a network with telemedical support by two academic hospitals. In a non-randomised, open intervention study, five community hospitals without specialised stroke care served as the control group, matched individually to the network hospitals by predefined characteristics. Stroke patients admitted consecutively to one of the participating hospitals between July 7, 2003, and March 31, 2005, were included in the study. Patients in network and control hospitals were assessed in the same manner and were followed up for vital status, living situation, and disability at 3 months. Poor outcome was defined by death, institutional care, or disability (Barthel index <60 or modified Rankin scale >3). Predefined indicators for quality of acute stroke care were achieved.

FINDINGS

A total of 5696 patients with a sudden, non-convulsive loss of neurological function who were diagnosed with having suspected stroke were admitted to the ten hospitals participating in the study. After exclusion, 3122 were included in the final analysis, of whom 1971 (63%) were treated in the network hospitals. All indicators related to quality of acute stroke care were more commonly met in the network than in the control hospitals. After 3 months, 44% of patients treated in network hospitals versus 54% treated in control hospitals had a poor outcome (p<0.0001). In multivariate regression analysis, treatment in network hospitals independently reduced the probability of a poor outcome (odds ratio 0.62, 95% CI 0.52-0.74; p<0.0001).

INTERPRETATION

Telemedical networks with academic stroke centres offer new and innovative approaches to improve acute stroke care at community level for stroke patients living in non-urban areas.

Fischer-344 rats are unsuitable for the MCAO filament model due to their cerebrovascular anatomy

Middle cerebral artery occlusion (MCAO) in Fischer-344 rats results in a small variance of infarct size. However, complications are frequent especially in aged Fisher-344 rats undergoing endovascular suture occlusion of the middle cerebral artery. Analyzing our experiences with 165 Wistar, 13 Sprague-Dawley and 10 F-344 rats, we compared the incidence of impossible thread advancement and subarachnoid hemorrhage, respectively. Magnetic resonance angiography (MRA) was applied to study the course of the internal carotid artery (ICA) in Fischer and Wistar rats. Finally, we performed a structured review of the literature from 1991 to 2005 evaluating reports on Fischer rats subjected to intraluminal filament MCAO. Complications like fruitless filament advancement or subarachnoid hemorrhage were found to be significantly more frequent in Fischer rats than in other strains. MRA revealed significantly more pronounced kinking of the ICA in F-344 than in Wistar rats. In seven publications available on filament MCAO in F-344 rats, complication rates of 50-100% were reported, corroborating our data. Surgical difficulties accompanied by high complication rates due to their cerebrovascular anatomy make Fischer rats unsuitable for filament MCAO. If the use of Fischer rats for studies on focal cerebral ischemia is indicated, other ischemia models than intraluminal suture occlusion should be chosen.

Failure of Schwann cells as supporting cells for adult neural progenitor cell grafts in the acutely injured spinal cord

Adult neural progenitor cells (NPC) co-grafted with fibroblasts replace cystic lesion defects and promote cell-contact-mediated axonal regeneration in the acutely injured spinal cord. Fibroblasts are required as a platform to maintain NPC within the lesion; however, they are suspected to create an inhospitable milieu for regenerating central nervous system (CNS) axons. Therefore, we thought to replace fibroblasts by primary Schwann cells, which might serve as a superior scaffold to maintain NPC within the lesion and might further enhance axon regrowth and remyelination following spinal cord injury. Adult rats underwent a cervical dorsal column transection immediately followed by transplantation of either NPC/Schwann cell or NPC/Schwann cell/fibroblast co-grafts. Animals receiving Schwann cell or fibroblast grafts alone, or Schwann cell/fibroblast co-grafts served as controls. At 3 weeks after injury/transplantation, histological analysis revealed that only fibroblast-containing grafts were able to replace the cystic lesion defect. In both co-cultures and co-grafts, Schwann cells and NPC were segregated. Almost all NPC migrated out of the graft into the adjacent host spinal cord. As a consequence, only peripheral-type myelin, but no CNS-type myelin, was detected within co-grafts containing NPC/Schwann cells. Corticospinal axon regeneration into Schwann-cell-containing co-grafts was reduced. Taken together, Schwann cells within NPC grafts contribute to remyelination. However, Schwann cells fail as a supporting platform to maintain NPC within the graft and impair CNS axon regeneration; this makes them an unfavorable candidate to support/augment NPC grafts following spinal cord injury.

Decrease of thalamic gray matter following limb amputation

Modern neuroscience has elucidated general mechanisms underlying the functional plasticity of the adult mammalian brain after limb deafferentation. However, little is known about possible structural alterations following amputation and chronic loss of afferent input in humans. Using voxel-based morphometry (VBM), based on high-resolution magnetic resonance images, we investigated the brain structure of 28 volunteers with unilateral limb amputation and compared them to healthy controls. Subjects with limb amputation exhibited a decrease in gray matter of the posterolateral thalamus contralateral to the side of the amputation. The thalamic gray matter differences were positively correlated with the time span after the amputation but not with the frequency or magnitude of coexisting phantom pain. Phantom limb pain was unrelated to thalamic structural variations, but was positively correlated to a decrease in brain areas related to the processing of pain. No gray matter increase was detected. The unilateral thalamic differences may reflect a structural correlate of the loss of afferent input as a secondary change following deafferentation.

Autonomic involvement in tick-borne encephalitis (TBE): report of five cases

BACKGROUND

Tick-borne encephalitis (TBE) is a viral infection of the CNS with significant acute and long-term morbidity. Dysfunction of the autonomic nervous system may be a potentially harmful complication of TBE.

MATERIAL AND METHODS

In a retrospective case series, 5 patients with acute TBE were evaluated for clinical signs of autonomic dysfunction and subject to autonomic testing. Heart rate variability (HRV) with 6 per minute deep breathing was performed between day 9 to 31 after onset of meningitis. Follow-up data were available in three cases.

RESULTS

All patients showed clinical signs of autonomic dysfunction, including upper and lower gastrointestinal tract symptoms, orthostatic hypotension, and urinary retention. A reduced HRV was observed in 4 patients, with sustained sinus tachycardia in 2 of them. The minimum of the HRV was reached 9 to 20 days after onset of meningitis. In one patient, normalization of the HRV occurred within 3 months.

CONCLUSION

Acute TBE can be associated with autonomic dysfunction including reduced HRV and tachycardia. Prospective studies are needed to analyze the incidence of autonomic dysfunction in TBE, and to clarify which patients have the highest risk for autonomic failure.

Results of G004, a phase IIb actively controlled clinical trial with the TGF-b2 targeted compound AP 12009 for recurrent anaplastic astrocytoma

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Background: In 3 phase I/II dose-escalation studies the TGF-β2 specific compound AP 12009 proved to be well tolerated and revealed an excellent safety profile. Furthermore, antitumor activity including complete tumor remissions was observed. Methods: G004 is an international open-label, actively controlled, dose finding phase IIb trial in adult patients with histopathologically confirmed recurrent high-grade glioma. 145 patients with recurrent anaplastic astrocytoma (AA, WHO grade III) or glioblastoma (GBM, WHO grade IV) were enrolled into the study. Objective of the current phase IIb study is to compare the efficacy and safety of two doses of AP 12009 and standard treatment. Patients were randomized to receive either one of two doses of AP 12009 (10 μM or 80 μM) or standard chemotherapy (TMZ or PCV). AP 12009 was administered intratumorally by CED. 134 patients received treatment and all of them have completed active treatment. Primary endpoint is tumor response by local and central MRI reading and survival. Results: Here we report on patients with recurrent AA (for GBM see separate Abstract). 38 patients with AA (68% male, 32% female; median age 39, range 22–60; median Karnofsky performance status: 90, range 70–100) were treated. 26 patients received AP 12009 (10 μM or 80 μM), 12 patients were treated with TMZ or PCV. Up to now, in 89 patients treated with AP 12009 (both AA and GBM patients) 6 SAEs possibly related to the study drug and 37 procedure related SAEs (92% mild or moderate) were documented. Partial and complete tumor responses were observed. Exact response rates will be determined after central MRI reading is completed. Responses in the AP 12009 groups are long lasting. The results confirm the good safety profile of AP 12009 as well as the efficacy data seen in phase I studies. The median overall survival is not yet reached. Conclusions: The long-term tumor free survival of several patients may actually hint towards a potential to cure some patients with this devastating disease. Phase III clinical trials in both AA and GBM patients are currently in preparation.

[Table: see text]

Results of G004, a phase IIb study in recurrent glioblastoma patients with the TGF-b2 targeted compound AP 12009

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Background: In high-grade glioma (HGG), TGF-β2 expression strongly correlates with tumor grade and is highly predictive of disease outcome. The compound AP 12009 inhibits TGF-β2 expression. Preclinical results revealed strong multimodal activity including reversal of TGF-β induced immunosuppression, inhibition of tumor cell migration and proliferation. In 3 preceding phase I/II dose escalation studies, 24 HGG patients had been treated with AP 12009. Methods: G004 is an international open-label, actively controlled, dose finding phase IIb study. Objective is a comparison of two doses of AP 12009 and standard chemotherapy for efficacy and safety. 145 patients with histopathologically confirmed recurrent anaplastic astrocytoma (AA, WHO grade III) or glioblastoma (GBM, WHO grade IV) were randomized into one of 3 treatment arms. 134 patients received treatment AP 12009 10μM, AP 12009 80μM or standard chemotherapy (TMZ or PCV). AP 12009 was applied locoregionally by convection-enhanced delivery during a 6-month active treatment period with 7-day-on, 7-day-off cycles. Primary endpoint is tumor response by local and central MRI reading. All patients have completed active treatment. Follow-up for survival and tumor response assessed by local and central MRI reading is ongoing. Results: Here we report on patients with recurrent GBM (AA see separate Abstract). 96 GBM patients (37% female, 63% male; median age 51 years, range 20–74; median Karnofsky performance status 90, range 70–100) have been treated. 63 GBM patients received AP 12009 (28 pt. 10 μM, 35 pt. 80 μM), 33 patients received standard chemotherapy. Data were evaluated by an independent Data and Safety Monitoring Board. Up to now, in 89 patients treated with AP 12009 (AA and GBM patients) 6 SAEs possibly related to the study drug and 37 procedure related SAEs (92% mild or moderate) were documented. Several long-term tumor responses were observed by local MRI reading. Exact response rates are being determined by central reading. Conclusions: Responses in patients treated with AP 12009 in both AA and GBM patients are long lasting with a good quality of life. Phase III clinical trials in AA and GBM patients are currently in preparation.

[Table: see text]

Combined regimen of temozolomide and liposomal pegylated doxorubicin in glioblastoma—Toxicity and efficacy

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Background: Temozolomide (Temodar, TMZ) recently showed promising efficacy in an EORTC trial on first-line therapy of glioblastoma (Stupp R, 2005). Pegylated liposomal doxorubicin (Caelyx, PEG-DOX) was evaluated in patients with recurrent high-grade glioma and showed an overall response rate of 40% (Hau P, 2002). Therefore, a combination of both agents seems promising. Methods: TMZ was given orally 75 mg/m2 daily during standard radiotherapy (initiation) and 150–200 mg/m2 days 1–5 in 28 days starting 4 weeks after radiotherapy (maintainance). PEG-DOX was given as a short-time infusion in a dose-escalation regimen once prior to radiotherapy and on days 1 and 15 starting 4 weeks after radiotherapy. PEG-DOX was escalated for 5 mg/m2 in groups of three patients starting with 5 mg/m2 (group 1) and a highest dose of 20 mg/m2 (group 4). Results: In the dose escalation part of this study, the regime detailed above was feasible, tolerable, and able to induce objective responses and stabilizations in patients with glioblastoma. In the first treatment group (5 mg/m2 of PEG-Dox), one out of 7 evaluable patients had a dose limiting toxicity (DLT). In the second, third and fourth treatment groups, the regimen was tolerated without DLT. Concerning efficacy in the “treated-patients” analysis of 18 patients, 1 had a partial response in MRI, and 12 patients had tumor stabilization 4 weeks after conclusion of radiotherapy. Only 5 patients progressed early. Twelve patients responded with progression free survival times of 13 to 76 weeks. One patient is still progression free after 120 weeks of treatment. Conclusion: As no DLT was observed in dose group 4, MTD was not reached and we proceed to the efficacy phase of the trial with PEG-DOX in a dose of 20 mg/m2. Seventeen patients are included so far. Results will be compared to the published study EORTC 26981/22981 (Stupp R et al., 2005) which did set a new standard in the first-line treatment of glioblastoma as survival times of more than 14 months and a 2-year overall survival of 26% were reached. Regarding the promising preliminary survival data of study RNOP-09, we expect even better results with the regimen used in this protocol.

[Table: see text]

Transforming growth factor-beta1 is a negative modulator of adult neurogenesis

Transforming growth factor (TGF)-beta1 has multiple functions in the adult central nervous system (CNS). It modulates inflammatory responses in the CNS and controls proliferation of microglia and astrocytes. In the diseased brain, TGF-beta1 expression is upregulated and, depending on the cellular context, its activity can be beneficial or detrimental regarding regeneration. We focus on the role of TGF-beta1 in adult neural stem cell biology and neurogenesis. In adult neural stem and progenitor cell cultures and after intracerebroventricular infusion, TGF-beta1 induced a long-lasting inhibition of neural stem and progenitor cell proliferation and a reduction in neurogenesis. In vitro, although TGF-beta1 specifically arrested neural stem and progenitor cells in the G0/1 phase of the cell cycle, it did not affect the self-renewal capacity and the differentiation fate of these cells. Also, in vivo, TGF-beta1 did not influence the differentiation fate of newly generated cells as shown by bromo-deoxyuridine incorporation experiments. Based on these data, we suggest that TGF-beta1 is an important signaling molecule involved in the control of neural stem and progenitor cell proliferation in the CNS. This might have potential implications for neurogenesis in a variety of TGF-beta1-associated CNS diseases and pathologic conditions.

Affective components and intensity of pain correlate with structural differences in gray matter in chronic back pain patients

Although chronic back pain is one of the most frequent reasons for permanent impairment in people under 65, the neurobiological mechanisms of chronification remain vague. Evidence suggests that cortical reorganisation, so-called functional plasticity, may play a role in chronic back pain patients. In the search for the structural counterpart of such functional changes in the CNS, we examined 18 patients suffering from chronic back pain with voxel-based morphometry and compared them to 18 sex and age matched healthy controls. We found a significant decrease of gray matter in the brainstem and the somatosensory cortex. Correlation analysis of pain unpleasantness and the intensity of pain on the day of scanning revealed a strong negative correlation (i.e. a decrease in gray matter with increasing unpleasantness/increasing intensity of pain) in these areas. Additionally, we found a significant increase in gray matter bilaterally in the basal ganglia and the left thalamus. These data support the hypothesis that ongoing nociception is associated with cortical and subcortical reorganisation on a structural level, which may play an important role in the process of the chronification of pain.

Effective silencing of EGFR with RNAi demonstrates non-EGFR dependent proliferation of glioma cells

The epidermal growth factor receptor (EGFR, ErbB1) is frequently dysregulated in a variety of solid human tumors, including malignant glioma. EGFR expression has been associated with disease progression, resistance to standard therapies and poor survival. The application of small interfering RNAs (siRNAs) has become an effective and highly specific tool to modulate gene expression, and a wide range of oncogenes have been silenced successfully. Here we show the siRNA-mediated down-regulation of EGFR in two established glioma cell lines with different EGFR expression levels (U373 MG, LN18). The expression of EGFR mRNA and protein was down-regulated by 70-90%. However, siRNA treatment had no inhibitory effect on cell proliferation, migration and activation status of EGFR-coupled signaling cascades. In accordance with these results, gene expression analysis with microarrays revealed only small, albeit specific changes in expression patterns. In conclusion, these data indicate that the specific down-regulation of EGFR might not be sufficient for a single agent therapeutic approach in malignant glioma.

Long-term outcome after hemicraniectomy for space occupying right hemispheric MCA infarction

OBJECTIVE

To examine the long-term prognosis in patients with 'malignant' supratentorial ischemia of the right hemisphere treated with hemicraniectomy, especially in respect to depression, with a focus on age as a possible predictor of outcome.

METHODS

We performed a prospective, long-term, follow-up examination in 23 survivors of 32 patients (mortality 28.1%) treated with hemicraniectomy for malignant middle cerebral artery (MCA) infarction of the right hemisphere, who were identified in our data bank since 1993. Long-term was defined as at least 20 months after craniectomy. Outcome data consisted of the items functionality, depression and quality of life. Tests applied included the Barthel Index (BI), the modified Rankin Scale (mRS), Beck Depression Inventory (BDI) and stroke-specific quality of life (QoL) scale.

RESULTS

Of the 23 patients 15 (65.2%) had a BI>or=60, 11 (47.8%) a mRS<4 and 9 (39.1%) a SS-QOL>or=60%, each representing a favourable outcome. In retrospect, 14 (60.9%) patients approved the surgery. Depression, i.e. a BDI>9, was diagnosed in 13 (56.5%) patients and 5 (38.5%) of them were treated with antidepressants. In a multiple linear regression analysis age at craniectomy was a predictor of a low BI (beta=-0.863; p=0.031), but not of the other outcome parameters.

CONCLUSIONS

Depression is a common and rarely treated long-term complication after 'malignant' right hemispheric ischemia. While high age is a strong predictor of poor functional outcome, it has no impact on depression and retrospective approval of craniectomy.

Gray matter decrease in patients with chronic tension type headache

Using MRI and voxel-based morphometry, the authors investigated 20 patients with chronic tension type headache (CTTH) and 20 patients with medication-overuse headache and compared them to 40 controls with no headache history. Only patients with CTTH demonstrated a significant gray matter decrease in regions known to be involved in pain processing. The finding implies that the alterations are specific to CTTH rather than a response to chronic head pain or chronification per se.

Novel truncating and missense mutations of the KCC3 gene associated with Andermann syndrome

Background: Andermann syndrome (OMIM 218000) is an autosomal recessive motor-sensory neuropathy associated with developmental and neurodegenerative defects. The cerebral MRI reveals a variable degree of agenesis of the corpus callosum. Recently, truncating mutations of the KCC3 gene (also known as SLC12A6) have been associated with Andermann syndrome.

Methods: The authors assessed clinically and genetically three isolated cases from Germany and Turkey with symptoms consistent with Andermann syndrome.

Results: The authors detected four novel mutations within the KCC3 gene in their patients: two different truncating mutations in the first patient, a homozygous truncating mutation in the second, and a homozygous missense mutation in the third patient. In contrast to the classic phenotype of the Andermann syndrome linked to truncating KCC3 mutations the phenotype and the course of the disease linked to the missense mutation appeared to be different (i.e., showing additional features like diffuse and widespread white matter abnormalities).

Conclusions: Not only truncating but also missense mutations of the KCC3 gene are associated with Andermann syndrome. Different types of KCC3 mutations may determine different clinical phenotypes.

Calcified neurocysticercosis lesions trigger symptomatic inflammation during antiparasitic therapy

We report a patient with neurocysticercosis who developed numerous cerebral edematous lesions while undergoing cysticidal therapy. These lesions outnumbered viable cystic lesions seen before therapy. Most new lesions were subsequently found to be associated with former calcifications not seen on initial MR imaging. Calcified neurocysticercosis lesions can trigger inflammatory reactions during therapy, and the number and location of calcified neurocysticercosis lesions may influence treatment decisions.

In vivo high-resolution MR imaging of neuropathologic changes in the injured rat spinal cord

BACKGROUND AND PURPOSE

MR imaging is the most comprehensive noninvasive means to assess structural changes in injured central nervous system (CNS) tissue in humans over time. The few published in vivo MR imaging studies of spinal cord injury in rodent models by using field strengths < or = 7T suffer from low spatial resolution, flow, and motion artifacts. The aim of this study was to assess the capacity of a 17.6T imaging system to detect pathologic changes occurring in a rat spinal cord contusion injury model ex vivo and in vivo.

METHODS

Seven adult female Fischer 344 rats received contusion injuries at thoracic level T10, which caused severe and reproducible lesions of the injured spinal cord parenchyma. Two to 58 days postinjury, high-resolution MR imaging was performed ex vivo (2) or in vivo in anesthetized rats (5 spinal cord injured + one intact control animal) by using 2D multisection spin- and gradient-echo imaging sequences, respectively, combined with electrocardiogram triggering and respiratory gating.

RESULTS

The acquired images provided excellent resolution and gray/white matter differentiation without significant artifacts. Signal intensity changes, which were detected with ex vivo and in vivo MR imaging following spinal cord injury, could be correlated with histologically defined structural changes such as edema, fibroglial scar, and hemorrhage.

CONCLUSIONS

These results demonstrate that MR imaging at 17.6T allows high-resolution structural analysis of spinal cord pathology after injury.

The promotion of oriented axonal regrowth in the injured spinal cord by alginate-based anisotropic capillary hydrogels

Appropriate target reinnervation and functional recovery after spinal cord injury depend on longitudinally directed regrowth of transected axons. To assess the capacity to promote directed axon regeneration, alginate-based highly anisotropic capillary hydrogels (ACH) were introduced into an axon outgrowth assay in vitro and adult rat spinal cord lesions in vivo. In an entorhino-hippocampal slice culture model, alginate-based scaffolds elicit highly oriented linear axon regrowth and appropriate target neuron reinnervation. Coating of alginate-based ACH with the extracellular matrix components collagen, fibronectin, poly L-ornithine and laminin did not alter the axon regrowth response as compared to uncoated alginate-based ACH. After implantation into acute cervical spinal cord lesions in adult rats, alginate-based ACH integrate into the spinal cord parenchyma without major inflammatory responses, maintain their anisotropic structure and in parallel to findings in vitro induce directed axon regeneration across the artificial scaffold. Furthermore, adult neural progenitor cells (NPC), which have been shown to promote cell-contact-mediated axon regeneration, can be seeded into alginate-based ACH as a prerequisite to further improve the regenerative capacity of these artificial growth supportive matrices. Thus, alginate-based ACH represent a promising strategy to induce directed nerve regrowth following spinal cord injury.

Relation between laterality and immune response after acute cerebral ischemia

OBJECTIVE

During the last 2 decades, right/left hemisphere dominance was supposed to affect the immune system differently. Experimental and clinical observations indicate that the left hemisphere plays a crucial role in the development of the immune system. The true relationship between immune response and acute ischemic stroke laterality remains to be elucidated.

METHODS

We studied acute right-handed stroke patients admitted to a single acute neurology department with a specialized stroke unit. Being part of our clinical protocol, blood samples were taken within the first 24 h after the onset of stroke symptoms. The medical record of each patient was reviewed, and demographic, clinical laboratory (key criteria: C-reactive protein, CRP, and white blood cell count, WBC) and neuroimaging information was retrieved. All data were presented descriptively, and bivariate test statistics, ANOVA (log-transformed data) or linear correlations were calculated.

RESULTS

Fifty-six of the 187 patients admitted to our Stroke Unit between October 2003 and March 2004 with different stroke subtypes according to the TOAST criteria were retrospectively evaluated in order to characterize the impact of stroke laterality on immunoregulatory response measured by CRP levels and WBC. Correlation analysis revealed that left-sided ischemic stroke yielded a significantly higher correlation between CRP levels and WBC. Following left-sided stroke, a more marked variability in CRP and WBC was found compared to patients with right-sided ischemic stroke, although ANOVA did not show significant differences between immune response values as a function of stroke subtypes.

CONCLUSIONS

We identified an association between stroke laterality and immunoregulatory response in patients with acute ischemic stroke. Left-sided stroke may be considered as a direct risk factor for infectious disease or immune deficits and should attract special attention. However, these preliminary results need be confirmed by controlled studies.

Striatal deafferentation increases dopaminergic neurogenesis in the adult olfactory bulb

Dopaminergic loss is known to be one of the major hallmarks of Parkinson disease (PD). In addition to its function as a neurotransmitter, dopamine plays significant roles in developmental and adult neurogenesis. Both dopaminergic deafferentation and stimulation modulate proliferation in the subventricular zone (SVZ)/olfactory bulb system as well as in the hippocampus. Here, we study the impact of 6-hydroxydopamine (6-OHDA) lesions to the medial forebrain bundle on proliferation and neuronal differentiation of newly generated cells in the SVZ/olfactory bulb axis in adult rats. Proliferation in the SVZ decreased significantly after dopaminergic deafferentation. However, the number of neural progenitor cells expressing the proneuronal cell fate determinant Pax-6 increased in the SVZ. Survival and quantitative cell fate analysis of newly generated cells revealed that 6-OHDA lesions induced opposite effects in the two different regions of neurogenesis in the olfactory bulb: a transient decrease in the granule cell layer contrasts to a sustained increase of newly generated neurons in the glomerular layer. These data point towards a shift in the ratio of newly generated interneurons in the olfactory bulb layers. Dopaminergic neurogenesis in the glomerular layer tripled after lesioning and consistent with this finding, the total number of tyrosine hydroxylase (TH)-positive cells increased. Thus, loss of dopaminergic input to the SVZ led to a distinct cell fate decision towards stimulation of dopaminergic neurogenesis in the olfactory bulb glomerular layer. This study supports the accumulating evidence that neurotransmitters play a crucial role in determining survival and differentiation of newly generated neurons.