Predictors of Neurological Worsening after Resection of Spinal Meningiomas

BACKGROUND

Due to the slow-growing nature of spinal meningiomas, they are mostly asymptomatic for a long time, and become symptomatic after the compression of the spinal cord or nerve roots. The aim of this study was to identify predictors for a poor clinical outcome after the surgical resection of spinal meningiomas and thereby to allow a preoperative identification of high-risk spinal meningiomas.

METHODS

Data acquisition was conducted as a single-center retrospective analysis. From 1 January 2004 to 31 December 2019, 121 patients who underwent surgical resection of a spinal meningioma were reviewed. Clinical and radiological data (such as tumor size, location, occupation ratio of the spinal canal, and the degree of spinal cord compression) were assessed. The functional clinical findings of the patients were recorded using the Karnofsky Performance Score, modified McCormick scale, and Frankel scale preoperatively, at discharge, and 3-6 months after surgery.

RESULTS

The mean patient age was 66 ± 13 years. A total of 104 (86%) patients were female and 17 (14%) were male. The thoracic spine (68%) was the most common location, followed by the cervical (29%) and lumbar (3%) spine. Preoperatively, 11.7% of patients were categorized as McCormick 1, 35.8% as 2, 39.2% as 3, 11.7% as 4, and 1.7% as 5. The neurological function of the patients with a functional deficit prior to surgery improved in 46% of the patients, remained unchanged in 52%, and worsened in 2% at discharge. At early follow-up, the proportions were 54%, 28%, and 5%, respectively. Preoperative Frankel scale was a significant predictor of a postoperative deterioration. Patients with Frankel score A to C preoperatively had a 9.2 times higher chance of clinical deterioration postoperatively (OR = 9.16). We found that the Frankel scale weakly correlated with the degree of spinal cord compression. In this study, other radiological parameters, such as the degree of cord compression and spinal canal occupation ratio, did not show a significant effect on the outcome.

CONCLUSIONS

Surgery of intraspinal meningiomas can be considered safe. Neurological function improves in a large proportion of patients after surgery. However, a relevant preoperative deficit according to the Frankel scale (grade A-C) was a significant predictor of a postoperative neurological deterioration.

Neuroanatomical changes of ionotropic glutamatergic and GABAergic receptor densities in male mice modeling idiopathic and syndromic autism spectrum disorder

Autism spectrum disorder (ASD) comprises a wide range of neurodevelopment conditions primarily characterized by impaired social interaction and repetitive behavior, accompanied by a variable degree of neuropsychiatric characteristics. Synaptic dysfunction is undertaken as one of the key underlying mechanisms in understanding the pathophysiology of ASD. The excitatory/inhibitory (E/I) hypothesis is one of the most widely held theories for its pathogenesis. Shifts in E/I balance have been proven in several ASD models. In this study, we investigated three mouse lines recapitulating both idiopathic (the BTBR strain) and genetic (Fmr1 and Shank3 mutants) forms of ASD at late infancy and early adulthood. Using receptor autoradiography for ionotropic excitatory (AMPA and NMDA) and inhibitory (GABAA) receptors, we mapped the receptor binding densities in brain regions known to be associated with ASD such as prefrontal cortex, dorsal and ventral striatum, dorsal hippocampus, and cerebellum. The individual mouse lines investigated show specific alterations in excitatory ionotropic receptor density, which might be accounted as specific hallmark of each individual line. Across all the models investigated, we found an increased binding density to GABAA receptors at adulthood in the dorsal hippocampus. Interestingly, reduction in the GABAA receptor binding density was observed in the cerebellum. Altogether, our findings suggest that E/I disbalance individually affects several brain regions in ASD mouse models and that alterations in GABAergic transmission might be accounted as unifying factor.

Striatal increase of dopamine receptor 2 density in idiopathic and syndromic mouse models of autism spectrum disorder

Autism spectrum disorder (ASD) comprises a wide range of neurodevelopmental phenotypes united by impaired social interaction and repetitive behavior. Environmental and genetic factors are associated with the pathogenesis of ASD, while other cases are classified as idiopathic. The dopaminergic system has a profound impact in the modulation of motor and reward-motivated behaviors, and defects in dopaminergic circuits are implicated in ASD. In our study, we compare three well-established mouse models of ASD, one idiopathic, the BTBR strain, and two syndromic, Fmr1 and Shank3 mutants. In these models, and in humans with ASD, alterations in dopaminergic metabolism and neurotransmission were highlighted. Still, accurate knowledge about the distribution of dopamine receptor densities in the basal ganglia is lacking. Using receptor autoradiography, we describe the neuroanatomical distribution of D1 and D2 receptors in dorsal and ventral striatum at late infancy and adulthood in the above-mentioned models. We show that D1 receptor binding density is different among the models irrespective of the region. A significant convergence in increased D2 receptor binding density in the ventral striatum at adulthood becomes apparent in BTBR and Shank3 lines, and a similar trend was observed in the Fmr1 line. Altogether, our results confirm the involvement of the dopaminergic system, showing defined alterations in dopamine receptor binding density in three well-established ASD lines, which may provide a plausible explanation to some of the prevalent traits of ASD. Moreover, our study provides a neuroanatomical framework to explain the utilization of D2-acting drugs such as Risperidone and Aripiprazole in ASD.

Anti-prothrombin autoantibodies enriched after infection with SARS-CoV-2 and influenced by strength of antibody response against SARS-CoV-2 proteins

Antiphospholipid antibodies (aPL), assumed to cause antiphospholipid syndrome (APS), are notorious for their heterogeneity in targeting phospholipids and phospholipid-binding proteins. The persistent presence of Lupus anticoagulant and/or aPL against cardiolipin and/or β2-glycoprotein I have been shown to be independent risk factors for vascular thrombosis and pregnancy morbidity in APS. aPL production is thought to be triggered by-among other factors-viral infections, though infection-associated aPL have mostly been considered non-pathogenic. Recently, the potential pathogenicity of infection-associated aPL has gained momentum since an increasing number of patients infected with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has been described with coagulation abnormalities and hyperinflammation, together with the presence of aPL. Here, we present data from a multicentric, mixed-severity study including three cohorts of individuals who contracted SARS-CoV-2 as well as non-infected blood donors. We simultaneously measured 10 different criteria and non-criteria aPL (IgM and IgG) by using a line immunoassay. Further, IgG antibody response against three SARS-CoV-2 proteins was investigated using tripartite automated blood immunoassay technology. Our analyses revealed that selected non-criteria aPL were enriched concomitant to or after an infection with SARS-CoV-2. Linear mixed-effects models suggest an association of aPL with prothrombin (PT). The strength of the antibody response against SARS-CoV-2 was further influenced by SARS-CoV-2 disease severity and sex of the individuals. In conclusion, our study is the first to report an association between disease severity, anti-SARS-CoV-2 immunoreactivity, and aPL against PT in patients with SARS-CoV-2.

C2orf69 mutations disrupt mitochondrial function and cause a multisystem human disorder with recurring autoinflammation

BACKGROUNDDeciphering the function of the many genes previously classified as uncharacterized open reading frame (ORF) would complete our understanding of a cell's function and its pathophysiology.METHODSWhole-exome sequencing, yeast 2-hybrid and transcriptome analyses, and molecular characterization were performed in this study to uncover the function of the C2orf69 gene.RESULTSWe identified loss-of-function mutations in the uncharacterized C2orf69 gene in 8 individuals with brain abnormalities involving hypomyelination and microcephaly, liver dysfunction, and recurrent autoinflammation. C2orf69 contains an N-terminal signal peptide that is required and sufficient for mitochondrial localization. Consistent with mitochondrial dysfunction, the patients showed signs of respiratory chain defects, and a CRISPR/Cas9-KO cell model of C2orf69 had similar respiratory chain defects. Patient-derived cells revealed alterations in immunological signaling pathways. Deposits of periodic acid-Schiff-positive (PAS-positive) material in tissues from affected individuals, together with decreased glycogen branching enzyme 1 (GBE1) activity, indicated an additional impact of C2orf69 on glycogen metabolism.CONCLUSIONSOur study identifies C2orf69 as an important regulator of human mitochondrial function and suggests that this gene has additional influence on other metabolic pathways.

Ablation of lysozyme M-positive cells prevents aircraft noise-induced vascular damage without improving cerebral side effects

Aircraft noise induces vascular and cerebral inflammation and oxidative stress causing hypertension and cardiovascular/cerebral dysfunction. With the present studies, we sought to determine the role of myeloid cells in the vascular vs. cerebral consequences of exposure to aircraft noise. Toxin-mediated ablation of lysozyme M+ (LysM+) myeloid cells was performed in LysMCreiDTR mice carrying a cre-inducible diphtheria toxin receptor. In the last 4d of toxin treatment, the animals were exposed to noise at maximum and mean sound pressure levels of 85 and 72 dB(A), respectively. Flow cytometry analysis revealed accumulation of CD45+, CD11b+, F4/80+, and Ly6G-Ly6C+ cells in the aortas of noise-exposed mice, which was prevented by LysM+ cell ablation in the periphery, whereas brain infiltrates were even exacerbated upon ablation. Aircraft noise-induced increases in blood pressure and endothelial dysfunction of the aorta and retinal/mesenteric arterioles were almost completely normalized by ablation. Correspondingly, reactive oxygen species in the aorta, heart, and retinal/mesenteric vessels were attenuated in ablated noise-exposed mice, while microglial activation and abundance in the brain was greatly increased. Expression of phagocytic NADPH oxidase (NOX-2) and vascular cell adhesion molecule-1 (VCAM-1) mRNA in the aorta was reduced, while NFκB signaling appeared to be activated in the brain upon ablation. In sum, we show dissociation of cerebral and peripheral inflammatory reactions in response to aircraft noise after LysM+ cell ablation, wherein peripheral myeloid inflammatory cells represent a dominant part of the pathomechanism for noise stress-induced cardiovascular effects and their central nervous counterparts, microglia, as key mediators in stress responses.

Principles and requirements for stroke recovery science

The disappointing results in bench-to-bedside translation of neuroprotective strategies caused a certain shift in stroke research towards enhancing the endogenous recovery potential of the brain. One reason for this focus on recovery is the much wider time window for therapeutic interventions which is open for at least several months. Since recently two large clinical studies using d-amphetamine or fluoxetine, respectively, to enhance post-stroke neurological outcome failed again it is a good time for a critical reflection on principles and requirements for stroke recovery science. In principal, stroke recovery science deals with all events from the molecular up to the functional and behavioral level occurring after brain ischemia eventually ending up with any measurable improvement of various clinical parameters. A detailed knowledge of the spontaneously occurring post-ischemic regeneration processes is the indispensable prerequisite for any therapeutic approaches aiming to modify these responses to enhance post-stroke recovery. This review will briefly illuminate the molecular mechanisms of post-ischemic regeneration and the principle possibilities to foster post-stroke recovery. In this context, recent translational approaches are analyzed. Finally, the principal and specific requirements and pitfalls in stroke recovery research as well as potential explanations for translational failures will be discussed.

Immune Cell Infiltration into the Brain After Ischemic Stroke in Humans Compared to Mice and Rats: a Systematic Review and Meta-Analysis

Although several studies have suggested that anti-inflammatory strategies reduce secondary infarct growth in animal stroke models, clinical studies have not yet demonstrated a clear benefit of immune modulation in patients. Potential reasons include systematic differences of post-ischemic neuroinflammation between humans and rodents. We here performed a systematic review and meta-analysis to summarize and compare the spatial and temporal distribution of immune cell infiltration in human and rodent stroke. Data on spatiotemporal distribution of immune cells (T cells, macrophages, and neutrophils) and infarct volume were extracted. Data from all rodent studies were pooled by means of a random-effect meta-analysis. Overall, 20 human and 188 rodent stroke studies were included in our analyses. In both patients and rodents, the infiltration of macrophages and neutrophils preceded the lymphocytic influx. Macrophages and neutrophils were the predominant immune cells within 72 h after infarction. Although highly heterogeneously across studies, the temporal profile of the poststroke immune response was comparable between patients and rodents. In rodent stroke, the extent of the immune cell infiltration depended on the duration and location of vessel occlusion and on the species. The density of infiltrating immune cells correlated with the infarct volume. In summary, we provide the first systematic analysis and comparison of human and rodent post-ischemic neuroinflammation. Our data suggest that the inflammatory response in rodent stroke models is comparable to that in patients with stroke. However, the overall heterogeneity of the post-ischemic immune response might contribute to the translational failure in stroke research.

Decreased hippocampal cell proliferation in mice with experimental antiphospholipid syndrome

The antiphospholipid syndrome (APS) is an autoimmune disease characterized by the presence of antiphospholipid antibodies, which may trigger vascular thrombosis with consecutive infarcts. However, cognitive dysfunctions representing one of the most commonest neuropsychiatric symptoms are frequently present despite the absence of any ischemic brain lesions. Data on the structural and functional basis of the neuropsychiatric symptoms are sparse. To examine the effect of APS on hippocampal neurogenesis and on white matter, we induced experimental APS (eAPS) in adult female Balb/C mice by immunization with β2-glycoprotein 1. To investigate cell proliferation in the dentate gyrus granular cell layer (DG GCL), eAPS and control mice (n = 5, each) were injected with 5-bromo-2'-deoxyuridine (BrdU) once a day for 10 subsequent days. Sixteen weeks after immunization, eAPS resulted in a significant reduction of BrdU-positive cells in the DG GCL compared to control animals. However, double staining with doublecortin and NeuN revealed a largely preserved neurogenesis. Ultrastructural analysis of corpus callosum (CC) axons in eAPS (n = 6) and control mice (n = 7) revealed no significant changes in CC axon diameter or g-ratio. In conclusion, decreased cellular proliferation in the hippocampus of eAPS mice indicates a limited regenerative potential and may represent one neuropathological substrate of cognitive changes in APS while evidence for alterations of white matter integrity is lacking.

Evaluation of the apparent diffusion coefficient in patients with recurrent glioblastoma under treatment with bevacizumab with radiographic pseudoresponse

BACKGROUND

Response Assessment in Neuro-Oncology Criteria (RANO), are used to asses response to first-line treatment of glioblastoma (GBM). Differentiation between response and pseudoresponse under treatment with Bevacizumab (BVZ) remains challenging. This study evaluates ADC changes in patients with radiographic pseudoresponse under treatment with (BVZ).

METHODS

Patients (n=40) with recurrent GBM under-treatment with BVZ underwent MRI before, two and four months after treatment with BVZ. In patients with radiological pseudoresponse (n=11), ADC analyses were performed. Areas with decreasing T1 contrast enhancement (CE) and FLAIR signal decrease were manually selected and compared to size and position matched healthy contralateral brain parenchyma.

RESULTS

Histogram based ADC (10^-6×mm²/s) of these patients decreased significantly (P<0.005) from baseline MRI (T1-CE, FLAIR: 1124.9±160.3, 1098.4±226.2, respectively) to 2months (781.3±110.7, 783.3±103.3) and remained stable during 4months (777.0±138.5, 784.4±155.4, all mean±1 SD), despite progressive disease. Mean ADC values of the healthy contralateral brain tissue remained stable (P>0.05) (ADC values: baseline: 786.2±110.7, 2months: 781.1±76.2, 4months: 804.1±86.2).

CONCLUSION

Treatment of GBM with BVZ leads to a decrease of ADC values in areas of pre-treatment T1-CE/FLAIR signal hyperintensity to levels of comparable with normal brain tissue. ADC values remained stable, even when progressive tumor growth was reported.

Neuronal Growth and Behavioral Alterations in Mice Deficient for the Psychiatric Disease-Associated Negr1 Gene

Neuronal growth regulator 1 (NEGR1), a member of the immunoglobulin superfamily cell adhesion molecule subgroup IgLON, has been implicated in neuronal growth and connectivity. In addition, genetic variants in or near the NEGR1 locus have been associated with obesity and more recently with learning difficulties, intellectual disability and psychiatric disorders. However, experimental evidence is lacking to support a possible link between NEGR1, neuronal growth and behavioral abnormalities. Initial expression analysis of NEGR1 mRNA in C57Bl/6 wildtype (WT) mice by in situ hybridization demonstrated marked expression in the entorhinal cortex (EC) and dentate granule cells. In co-cultures of cortical neurons and NSC-34 cells overexpressing NEGR1, neurite growth of cortical neurons was enhanced and distal axons occupied an increased area of cells overexpressing NEGR1. Conversely, in organotypic slice co-cultures, Negr1-knockout (KO) hippocampus was less permissive for axons grown from EC of β-actin-enhanced green fluorescent protein (EGFP) mice compared to WT hippocampus. Neuroanatomical analysis revealed abnormalities of EC axons in the hippocampal dentate gyrus (DG) of Negr1-KO mice including increased numbers of axonal projections to the hilus. Neurotransmitter receptor ligand binding densities, a proxy of functional neurotransmitter receptor abundance, did not show differences in the DG of Negr1-KO mice but altered ligand binding densities to NMDA receptor and muscarinic acetylcholine receptors M1 and M2 were found in CA1 and CA3. Activity behavior, anxiety-like behavior and sensorimotor gating were not different between genotypes. However, Negr1-KO mice exhibited impaired social behavior compared to WT littermates. Moreover, Negr1-KO mice showed reversal learning deficits in the Morris water maze and increased susceptibility to pentylenetetrazol (PTZ)-induced seizures. Thus, our results from neuronal growth assays, neuroanatomical analyses and behavioral assessments provide first evidence that deficiency of the psychiatric disease-associated Negr1 gene may affect neuronal growth and behavior. These findings might be relevant to further evaluate the role of NEGR1 in cognitive and psychiatric disorders.

Prevention of an increase in cortical ligand binding to AMPA receptors may represent a novel mechanism of endogenous brain protection by G-CSF after ischemic stroke

PURPOSE

Using G-CSF deficient mice we recently demonstrated neuroprotective properties of endogenous G-CSF after ischemic stroke. The present follow-up study was designed to check, whether specific alterations in ligand binding densities of excitatory glutamate or inhibitory GABAA receptors may participate in this effect.

METHODS

Three groups of female mice were subjected to 45 minutes of MCAO: wildtype, G-CSF deficient and G-CSF deficient mice substituted with G-CSF. Infarct volumes were determined after 24 hours and quantitative in vitro receptor autoradiography was performed using [3H]MK-801, [3H]AMPA and [3H]muscimol for labeling of NMDA, AMPA and GABAA receptors, respectively. Ligand binding densities were analyzed in regions in the ischemic core, peri-infarct areas and corresponding contralateral regions.

RESULTS

Infarct volumes did not significantly differ between the experimental groups. Ligand binding densities of NMDA and GABAA receptors were widely in the same range. However, AMPA receptor binding densities in G-CSF deficient mice were substantially enhanced compared to wildtype mice. G-CSF substitution in mice lacking G-CSF largely reversed this effect.

CONCLUSIONS

Although infarct volumes did not differ 24 hours after ischemia the increase of AMPA receptor binding densities in G-CSF deficient mice may explain the bigger infarcts previously observed at later time-points with the same stroke model.

Ischemic stroke: experimental models and reality

The vast majority of cerebral stroke cases are caused by transient or permanent occlusion of a cerebral blood vessel (“ischemic stroke”) eventually leading to brain infarction. The final infarct size and the neurological outcome depend on a multitude of factors such as the duration and severity of ischemia, the existence of collateral systems and an adequate systemic blood pressure, etiology and localization of the infarct, but also on age, sex, comorbidities with the respective multimedication and genetic background. Thus, ischemic stroke is a highly complex and heterogeneous disorder. It is immediately obvious that experimental models of stroke can cover only individual specific aspects of this multifaceted disease. A basic understanding of the principal molecular pathways induced by ischemia-like conditions comes already from in vitro studies. One of the most frequently used in vivo models in stroke research is the endovascular suture or filament model in rodents with occlusion of the middle cerebral artery (MCA), which causes reproducible infarcts in the MCA territory. It does not require craniectomy and allows reperfusion by withdrawal of the occluding filament. Although promptly restored blood flow is far from the pathophysiology of spontaneous human stroke, it more closely mimics the therapeutic situation of mechanical thrombectomy which is expected to be increasingly applied to stroke patients. Direct transient or permanent occlusion of cerebral arteries represents an alternative approach but requires craniectomy. Application of endothelin-1, a potent vasoconstrictor, allows induction of transient focal ischemia in nearly any brain region and is frequently used to model lacunar stroke. Circumscribed and highly reproducible cortical lesions are characteristic of photothrombotic stroke where infarcts are induced by photoactivation of a systemically given dye through the intact skull. The major shortcoming of this model is near complete lack of a penumbra. The two models mimicking human stroke most closely are various embolic stroke models and spontaneous stroke models. Closeness to reality has its price and goes along with higher variability of infarct size and location as well as unpredictable stroke onset in spontaneous models versus unpredictable reperfusion in embolic clot models.

Functional Improvement after Photothrombotic Stroke in Rats Is Associated with Different Patterns of Dendritic Plasticity after G-CSF Treatment and G-CSF Treatment Combined with Concomitant or Sequential Constraint-Induced Movement Therapy

We have previously shown that granulocyte-colony stimulating factor (G-CSF) treatment alone, or in combination with constraint movement therapy (CIMT) either sequentially or concomitantly, results in significantly improved sensorimotor recovery after photothrombotic stroke in rats in comparison to untreated control animals. CIMT alone did not result in any significant differences compared to the control group (Diederich et al., Stroke, 2012;43:185-192). Using a subset of rat brains from this former experiment the present study was designed to evaluate whether dendritic plasticity would parallel improved functional outcomes. Five treatment groups were analyzed (n = 6 each) (i) ischemic control (saline); (ii) CIMT (CIMT between post-stroke days 2 and 11); (iii) G-CSF (10 μg/kg G-CSF daily between post-stroke days 2 and 11); (iv) combined concurrent group (CIMT plus G-CSF) and (v) combined sequential group (CIMT between post-stroke days 2 and 11; 10 μg/kg G-CSF daily between post-stroke days 12 and 21, respectively). After impregnation of rat brains with a modified Golgi-Cox protocol layer V pyramidal neurons in the peri-infarct cortex as well as the corresponding contralateral cortex were analyzed. Surprisingly, animals with a similar degree of behavioral recovery exhibited quite different patterns of dendritic plasticity in both peri-lesional and contralesional areas. The cause for these patterns is not easily to explain but puts the simple assumption that increased dendritic complexity after stroke necessarily results in increased functional outcome into perspective.

Mice with experimental antiphospholipid syndrome display hippocampal dysfunction and a reduction of dendritic complexity in hippocampal CA1 neurones

AIMS

The antiphospholipid syndrome (APS) is an autoimmune disease characterized by high titres of auto-antibodies (aPL) leading to thrombosis and consequent infarcts. However, many affected patients develop neurological symptoms in the absence of stroke. Similarly, in a mouse model of this disease (eAPS), animals consistently develop behavioural abnormalities despite lack of ischemic brain injury. Therefore, the present study was designed to identify structural alterations of hippocampal neurones underlying the neurological symptoms in eAPS.

METHODS

Adult female Balb/C mice were subjected to either induction of eAPS by immunization with β2-Glycoprotein 1 or to a control group. After sixteen weeks animals underwent behavioural and cognitive testing using Staircase test (experiment 1 and 2) and Y-maze alternation test (experiment 1) and were tested for serum aPL levels (both experiments). Animals of experiment 1 (n = 7/group) were used for hippocampal neurone analysis using Golgi-Cox staining. Animals of experiment 2 (n = 7/group) were used to analyse molecular markers of total dendritic integrity (MAP2), presynaptic plasticity (synaptobrevin 2/VAMP2) and dendritic spines (synaptopodin) using immunohistochemistry.

RESULTS

eAPS mice developed increased aPL titres and presented with abnormal behaviour and impaired short term memory. Further, they revealed a reduction of dendritic complexity of hippocampal CA1 neurones as reflected by decreased dendritic length, arborization and spine density, respectively. Additional decrease of the spine-associated protein expression of Synaptopodin points to dendritic spines as major targets in the pathological process.

CONCLUSION

Reduction of hippocampal dendritic complexity may represent the structural basis for the behavioural and cognitive abnormalities of eAPS mice.

Distribution of the hematopoietic growth factor G-CSF and its receptor in the adult human brain with specific reference to Alzheimer's disease

The granulocyte colony-stimulating factor (G-CSF), being a member of the hematopoietic growth factor family, is also critically involved in controlling proliferation and differentiation of neural stem cells. Treatment with G-CSF has been shown to result in substantial neuroprotective and neuroregenerative effects in various experimental models of acute and chronic diseases of the central nervous system. Although G-CSF has been tested in a clinical study for treatment of acute ischemic stroke, there is only fragmentary data on the distribution of this cytokine and its receptor in the human brain. Therefore, the present study was focused on the immunohistochemical analysis of the protein expression of G-CSF and its receptor (G-CSF R) in the adult human brain. Since G-CSF has been shown not only to exert neuroprotective effects in animal models of Alzheimer's disease (AD) but also to be a candidate for clinical treatment, we have also placed an emphasis on the regulation of these molecules in this neurodegenerative disease. One major finding is that both G-CSF and G-CSF R were ubiquitously but not uniformly expressed in neurons throughout the CNS. Protein expression of G-CSF and G-CSF R was not restricted to neurons but was also detectable in astrocytes, ependymal cells, and choroid plexus cells. However, the distribution of G-CSF and G-CSF R did not substantially differ between AD brains and control, even in the hippocampus, where early neurodegenerative changes typically occur.

Altered receptor binding densities in experimental antiphospholipid syndrome despite only moderately enhanced autoantibody levels and absence of behavioral features

Experimental antiphospholipid syndrome (eAPS) in Balb/c mice causes neuropsychiatric abnormalities including hyperactivity, increased explorative behavior and cognitive deficits. Recently, we have demonstrated that these behavioral changes were linked to an upregulation of serotonergic 5-HT1A receptor binding densities in cortical and hippocampal regions while excitatory and inhibitory neurotransmitter receptors remain largely unchanged. To examine whether the observed behavioral features depend on a critical antibody concentration, mice with only moderately enhanced antiphospholipid antibodies (aPL), about 50-80% of high levels, were analyzed and compared to controls. The staircase test was used to test animals for hyperactivity and explorative behavior. The brains were analyzed for tissue integrity and inflammation. Ligand binding densities of NMDA, AMPA, GABAA, 5-HT1A, M1 and M2 muscarinic acetylcholine receptors, respectively, were analyzed by in vitro receptor autoradiography and compared to brains of mice from our previous study with high levels of aPL. Mice with only moderately enhanced aPL did not develop significant behavioral changes. Brain parenchyma remained intact and neither inflammation nor glial activation was detectable. However, there was a significant decrease of NMDA receptor binding densities in the motor cortex as well as an increase in M1 binding densities in cortical and hippocampal regions, whereas the other receptors analyzed were not altered. Lack of neuropsychiatric symptoms may be due to modulations of receptors resulting in normal behavior. In conclusion, our results support the hypothesis that high levels of aPL are required for the manifestation of neuropsychiatric involvement while at lower antibody levels compensatory mechanisms may preserve normal behavior.

Neurological impairment in experimental antiphospholipid syndrome is associated with increased ligand binding to hippocampal and cortical serotonergic 5-HT1A receptors

The antiphospholipid syndrome (APS) is an autoimmune disease where the presence of high titers of circulating autoantibodies causes thrombosis with consecutive infarcts. In experimental APS (eAPS), a mouse model of APS, behavioral abnormalities develop in the absence of vessel occlusion or infarcts. Using brain hemispheres of control and eAPS mice with documented neurological and cognitive deficits, we checked for lymphocytic infiltration, activation of glia and macrophages, as well as alterations of ligand binding densities of various neurotransmitter receptors to unravel the molecular basis of this abnormal behavior. Lymphocytic infiltrates were immunohistochemically characterized using antibodies against CD3, CD4, CD8 and forkhead box P3 (Foxp3), respectively. GFAP, Iba1 and CD68-immunohistochemistry was performed, to check for activation of astrocytes, microglia and macrophages. Ligand binding densities of NMDA, AMPA, GABAA and 5-HT1A receptors were analyzed by in vitro receptor autoradiography. No significant inflammatory reaction occurred in eAPS mice. There was neither activation of astrocytes or microglia nor accumulation of macrophages. Binding values of excitatory and inhibitory neurotransmitter receptors were largely unchanged. However, ligand binding densities of the modulatory serotonergic 5-HT1A receptors in the hippocampus and in the primary somatosensory cortex of eAPS mice were significantly upregulated which is suggested to induce the behavioral abnormalities observed.

Citicoline enhances neuroregenerative processes after experimental stroke in rats

BACKGROUND AND PURPOSE

The neuroprotective potential of citicoline in acute ischemic stroke has been shown in many experimental studies and, although the exact mechanisms are still unknown, a clinical Phase III trial is currently underway. Our present study was designed to check whether citicoline also enhances neuroregeneration after experimental stroke.

METHODS

Forty Wistar rats were subjected to photothrombotic stroke and treated either with daily injections of citicoline (100 mg/kg) or vehicle for 10 consecutive days starting 24 hours after ischemia induction. Sensorimotor tests were performed after an adequate training period at Days 1, 10, 21, and 28 after stroke. Then brains were removed and analyzed for infarct size, glial scar formation, neurogenesis, and ligand binding densities of excitatory and inhibitory neurotransmitter receptors.

RESULTS

Animals treated with citicoline showed a significantly better neurological outcome at Days 10, 21, and 28 after ischemia, which could not be attributed to differences in infarct volumes or glial scar formation. However, neurogenesis in the dentate gyrus, subventricular zone, and peri-infarct area was significantly increased by citicoline. Furthermore, enhanced neurological outcome after citicoline treatment was associated with a shift toward excitation in the perilesional cortex.

CONCLUSIONS

Our present data demonstrate that, apart from the well-known neuroprotective effects in acute ischemic stroke, citicoline also possesses a substantial neuroregenerative potential. Thanks to its multimodal effects, easy applicability, and history as a well-tolerated drug, promising possibilities of neurological treatment including chronic stroke open up.

[The unstable upper ankle joint. Treatment of acute ligament rupture--a review of the literature]

Acute lateral ankle ligament sprains represent a very frequent examinated and treated injury in the daily traumatological routine. A cursory review of recent articles published on this subject gives a confusing picture regarding diagnosis and treatment of such injuries. An air of controversy surrounds the interpretation of diagnostic x-rays and the management of these common ankle problems. This review article is to summarize current thoughts of different aspects concerning the treatment of acute lateral ankle ligament sprains.

Inadequate history as a barrier to immunization

OBJECTIVES

To evaluate how lack of immunization history contributes to missed opportunities for immunization and to document the effort required to obtain immunization history.

DESIGN

Cross-sectional.

SETTING

Urban, inner-city primary care pediatric clinic serving a low-income, multiethnic population.

PATIENTS

Ninety-five new patients seen for either well-child care (53 patients) or acute illnesses (42 patients) during a 4-month period in 1993. Fifty-nine patients were aged 3 to 59 months and 36 were aged 5 to 15 years.

MEASUREMENTS

Efforts to obtain immunization history were documented by means of a standardized data collection form.

RESULTS

Immunization history was obtained for only 26 (27%) of 95 patients during the initial visit. Caregivers of 74 (78%) of 95 patients did not bring immunization records to the initial visit; they were no more likely to bring records for well-child care than for acute care or for younger vs older children. Parents brought immunization records more often than did nonparents. A total of 145 telephone calls were made and 30 letters were sent in an attempt to obtain immunization histories. Immunization records were never found for 10 new patients (11%). Thirty-two patients (34%) were found to be lacking immunizations. Of these, only three patients had contraindications to immunization at the initial visit. Therefore, in one third of our new patients, opportunities to immunize were missed solely because their immunization records were unavailable at the initial visit. In another one third of cases, caregivers had incorrectly believed their child's immunizations to be up to date.

CONCLUSIONS

Opportunities to immunize children were often missed because of a lack of immunization history. Our experience supports the need for improved documentation of immunization histories.