Antibody and cytokine levels in humans fed on by the common bedbug, Cimex lectularius L.

Little is known about cimicosis, the resultant dermal reaction from feeding activity by the common bedbug, Cimex lectularius L. We fed C. lectularius on human study subjects four times over four weeks and measured serum cytokine and antibody levels, and subjects recorded any cimicosis. The average time for subjects to develop cimicosis decreased with each feeding from 8.4, to 2.1, 1.5 and 1.3 days, respectively. There were no significant changes in total IgG, IgG1, IgG2, IgG4 or IgE levels between the first and fourth bedbug feedings, but there was a significant decrease in total IgG3 levels (P<.001). IgG4 was not required for cimicosis. Higher IgG2 and IgG4 levels at study visit 4 were associated with an increased duration of cimicosis (P=.04) and lower pruritis (P=.03), respectively. There were no significant changes in serum TNF-α, IL-1ß, IL-4, IL-5, IL-6, IL-10, IFN-γ and IL-17A levels before and one hour after the C. lectularius feeding. Lower post-C. lectularius feeding IL-6 levels were associated with increased pruritis (P=.001) and the time to maximum pruritis (P=.04), respectively. Higher post-C. lectularius feeding IL-5 levels were associated with a longer duration of pruritis (P=.05).

Polarization Engineering in Photonic Crystal Waveguides for Spin-Photon Entanglers.

By performing a full analysis of the projected local density of states (LDOS) in a photonic crystal waveguide, we show that phase plays a crucial role in the symmetry of the light-matter interaction. By considering a quantum dot (QD) spin coupled to a photonic crystal waveguide (PCW) mode, we demonstrate that the light-matter interaction can be asymmetric, leading to unidirectional emission and a deterministic entangled photon source. Further we show that understanding the phase associated with both the LDOS and the QD spin is essential for a range of devices that can be realized with a QD in a PCW. We also show how suppression of quantum interference prevents dipole induced reflection in the waveguide, and highlight a fundamental breakdown of the semiclassical dipole approximation for describing light-matter interactions in these spin dependent systems.

Repeat instability in the 27-39 CAG range of the HD gene in the Venezuelan kindreds: Counseling implications.

The instability of the CAG repeat size of the HD gene when transmitted intergenerationally has critical implications for genetic counseling practices. In particular, CAG repeats between 27 and 35 have been the subject of debate based on small samples. To address this issue, we analyzed allelic instability in the Venezuelan HD kindreds, the largest and most informative families ascertained for HD. We identified 647 transmissions. Our results indicate that repeats in the 27-35 CAG range are highly stable. Out of 69 transmitted alleles in this range, none expand into any penetrant ranges. Contrastingly, 14% of alleles transmitted from the incompletely penetrant range (36-39 CAGs) expand into the completely penetrant range, characterized by alleles with 40 or more CAG repeats. At least 12 of the 534 transmissions from the completely penetrant range contract into the incompletely penetrant range of 36-39 CAG repeats. In these kindreds, none of the individuals with 27-39 CAGs were symptomatic, even though they ranged in age from 11 to 82 years. We expect these findings to be helpful in updating genetic counseling practices.

Absence of alpha-synuclein mRNA expression in normal and multiple system atrophy oligodendroglia.

alpha-Synuclein is a major constituent of glial cytoplasmic inclusions (GCIs), which are pathognomic for multiple system atrophy (MSA). We have previously demonstrated that in normal human brain, alpha-synuclein mRNA has a restricted pattern of neuronal expression and no apparent glial expression. The current study used double-label in situ hybridization to determine if alpha-synuclein mRNA is expressed by oligodendroglia of MSA cases. Analysis of MSA brain tissue revealed depletion of regional signal for this transcript in many brain areas due to extensive neurodegeneration. Cellular analysis of oligodendroglia in crus cerebri, a GCI-rich region ventral to substantia nigra, revealed an absence of alpha-synuclein mRNA signal in control and MSA cases. However, an abundance of this transcript was detected in melanin-containing neurons of substantia nigra. Therefore, oligodendroglia do not express alpha-synuclein mRNA in control and MSA cases suggesting that involvement of alpha-synuclein in GCI pathology of MSA is due to its ectopic presence in oligodendroglia.

EFNS guideline on the diagnosis and management of alcohol-related seizures: report of an EFNS task force.

Despite being a considerable problem in neurological practice and responsible for one-third of seizure-related admissions, there is little consensus as to the optimal investigation and management of alcohol-related seizures. The final literature search was undertaken in September 2004. Consensus recommendations are given graded according to the EFNS guidance regulations. To support the history taking, use of a structured questionnaire is recommended. When the drinking history is inconclusive, elevated values of carbohydrate-deficient transferrin and/or gammaglutamyl transferase can support a clinical suspicion. A first epileptic seizure should prompt neuroimaging (CT or MRI). Before starting any carbohydrate containing fluids or food, patients presenting with suspected alcohol overuse should be given prophylactic thiamine parenterally. After an alcohol withdrawal seizure (AWS), the patient should be observed in hospital for at least 24 h and the severity of withdrawal symptoms needs to be followed. For patients with no history of withdrawal seizures and mild to moderate withdrawal symptoms, routine seizure preventive treatment is not necessary. Generally, benzodiazepines are efficacious and safe for primary and secondary seizure prevention; diazepam or, if available, lorazepam, is recommended. The efficacy of other drugs is insufficiently documented. Concerning long-term recommendations for non-alcohol dependent patients with partial epilepsy and controlled seizures, small amounts of alcohol may be safe. Alcohol-related seizures require particular attention both in the diagnostic work-up and treatment. Benzodiazepines should be chosen for the treatment and prevention of recurrent AWS.

Differential loss of striatal projection systems in Huntington's disease: a quantitative immunohistochemical study.

Prior studies suggest differences exist among striatal projection neuron types in their vulnerability to Huntington's disease (HD). In the present study, we immunolabeled the fibers and terminals of the four main types of striatal projection neuron in their target areas for substance P, enkephalin, or glutamic acid decarboxylase (GAD), and used computer-assisted image analysis to quantify the abundance of immunolabeled terminals in a large sample of HD cases ranging from grade 0 to grade 4 [J. Neuropathol. Exp. Neurol. 44 (1985) 559], normalized to labeling in control human brains. Our goal was to characterize the relative rates of loss of the two striatopallidal projection systems (to the internal versus the external pallidal segments) and the two striatonigral projections systems (to pars compacta versus pars reticulata). The findings for GAD and the two neuropeptides were similar--the striatal projection to the external pallidal segment was the most vulnerable, showing substantial loss by grade 1. Loss of fibers in both subdivisions of the substantia nigra was also already great by grade 1. By contrast, the loss in the striatal projection system to the internal segment of globus pallidus proceeded more gradually. By grade 4 of HD, however, profound loss in all projection systems was apparent. These findings support the notion that the striatal neurons preferentially projecting to the internal pallidal segment are, in fact, less vulnerable in HD than are the other striatal projection neuron types.

Tyrosine phosphorylation of the metabotropic glutamate receptor mGluR5 in striatal neurons.

Protein phosphorylation, controlled by the coordinated actions of phosphatases and kinases, is an important regulatory mechanism in synaptic transmission and other neurophysiological processes. Ionotropic glutamate receptors are known targets of phosphorylation on serine, threonine and tyrosine residues, with functional consequences for cell excitability, plasticity and toxicity. While phosphorylation of metabotropic glutamate receptors (mGluRs) also impacts critical cellular processes, there has been no evidence for direct tyrosine phosphorylation of mGluRs. In the present study, anti-phosphotyrosine and specific mGluR antibodies were used to detect tyrosine-phosphorylated mGluRs in rat brain. In particular, we found that mGluR5 is an abundant phosphotyrosine protein in vivo as well as in primary striatal neurons and tissue slices in vitro. The protein phosphatase inhibitor pervanadate robustly increased the amount of tyrosine-phosphorylated mGluR5, suggesting the receptor is subject to an endogenous, active cycle of phosphorylation and dephosphorylation. Furthermore, NMDA treatment also increased the amount of tyrosine-phosphorylated mGluR5, suggesting these endogenous phosphorylation regulatory mechanisms can be used to mediate crosstalk between synaptic glutamate receptors. While mGluR5-stimulated phosphoinositide hydrolysis appears to be unaltered by pervanadate treatment, tyrosine phosphorylation of mGluR5 may be important in trafficking, anchoring, or signaling of the receptor through G protein-independent pathways.

The role of group I and group II metabotropic glutamate receptors in modulation of striatal NMDA and quinolinic acid toxicity.

Excitotoxic lesions of the striatum are mediated by the combined activity of N-methyl-d-aspartate (NMDA) receptors and metabotropic glutamate receptors (mGluRs). Intrastriatal injection of the NMDA receptor agonists NMDA or quinolinic acid creates large lesions, but in rats that have been decorticated to remove endogenous glutamatergic input, NMDA and quinolinic acid are no longer toxic. We report that NMDA toxicity can be restored in decorticated animals by coinjection of the group I mGluR agonists t-ACPD, t-ADA, or CHPG. In addition, injections of two group I mGluR antagonists, AIDA and (S)-4C3HPG, can protect against striatal lesions produced by quinolinic acid or NMDA injections in normal rats by blocking activation of group I mGluRs. The group II mGluR agonist APDC fails to protect against quinolinic acid or NMDA toxicity in intact animals or to restore NMDA toxicity in decorticated animals, suggesting that the role of group II receptors in this excitotoxic model is minimal. These observations confirm the important role of group I mGluRs in excitotoxicity and identify these receptors as promising targets for therapeutic intervention in neurodegenerative disease processes.

Glutamate receptor dysregulation in the hippocampus of transgenic mice carrying mutated human amyloid precursor protein.

Alzheimer's disease transgenic mice overexpressing human amyloid precursor protein (hAPP) with the Swedish double mutation (hAPP(Sw)) develop age-related amyloid deposition and behavioral and electrophysiologic changes by an unknown mechanism. Analysis of glutamatergic receptor subtypes in 4- and 15-month-old heterozygous hAPP(Sw) transgenic mice revealed a selective increase in AMPA receptor binding in the hippocampus of 15-month-old transgenic mice, which have established cortical and hippocampal amyloid deposits. There were no significant alterations of GluR1, GluR2, and GluR4 protein expression by semiquantitative confocal analysis or GluR1 mRNA by in situ hybridization. There was no significant alteration in NMDA, in group I and II metabotropic glutamate and in muscarinic receptor binding, or in striatal dopamine and adenosine receptor binding in 15-month-old mice. These data suggest that mutant APP overexpression or age-related amyloid deposition produce a subtle specific alteration in hippocampal glutamate receptors with aging.

The prognostic significance of midline shift at presentation on survival in patients with glioblastoma multiforme.

PURPOSE: While patients with glioblastoma multiforme (GBM) who present with midline shift have a presumably worse prognosis, there is little literature evaluating the prognostic significance of this presentation in multivariate analysis in the context of other known prognostic factors. METHODS AND MATERIALS: From March 1981 to September 1993, 219 patients underwent irradiation for intracranial glioma at our institution. One hundred fourteen patients with a diagnosis of a primary GBM were analyzed for the influence of the presence of midline shift at diagnosis on survival with respect to other known prognostic factors, including age, Karnofsky performance status (KPS), and extent of surgery. Eighty-five patients (74%) presented with midline shift. Surgical treatment consisted of subtotal/total resection in 86 patients (75%). Among patients presenting with midline shift, 68 (80%) underwent subtotal/total resection before irradiation. RESULTS: Multivariate analysis of the entire cohort of patients found none of the potential prognostic factors analyzed to significantly influence survival. The overall median survival was 6 months. However, when multivariate analysis was limited to patients with a KPS of > or = 70, only the presence of midline shift and age were found to significantly influence survival. Patients with a KPS > or = 70 and with midline shift present at diagnosis had a median survival of 8 months, as compared to 14 months for those not having midline shift at presentation (p = 0.04). Patients with a KPS > or = 70 and age > 50 years had a median survival of 5 months as compared to 11 months for those < or = 50 (p = 0.02). CONCLUSION: In this series, where 80% of patients who presented with a midline shift underwent decompressive resection of GBM before irradiation, the presence of midline shift at diagnosis remained an independent prognostic factor influencing survival among good performance status patients. While the role of decompressive surgery in this setting is likely of some benefit, the extent of this benefit remains to be defined.

Preliminary report of a phase I study of combined fractionated stereotactic radiosurgery and conventional external beam radiation therapy for unfavorable gliomas.

PURPOSE: To determine the tolerance and toxicities of fractionated stereotactic radiosurgery (FSRS) given in combination with conventional external beam radiation therapy (CEBRT). METHODS AND MATERIALS: From March 1995 to September 1998, 14 patients with previously unirradiated and unfavorable glioma (malignant glioma, n = 8; unfavorable low-grade glioma, n = 5; and recurrent glioma, n = 1) were stratified into 3 groups according to tumor volume (TV) to determine the initial FSRS dose schedule: Group A (n = 3): TV /=50% reduction, n = 2) or minor (>20% reduction, n = 9) imaging response. Follow-up ranged from 9 to 51 months (median 15 months), with 7 patients alive at 22-51 months. CONCLUSIONS: Imaging response and the ability of these patients with unfavorable intracranial gliomas to complete therapy without interruption or experiencing disease progression is very encouraging. Excessive toxicity of combined FSRS and CEBRT as evaluated thus far in this study was seen for patients with group B/C lesions. Evaluation of this novel treatment strategy with dose modification is ongoing.

Decreased expression of striatal signaling genes in a mouse model of Huntington's disease.

To understand gene expression changes mediated by a polyglutamine repeat expansion in the human huntingtin protein, we used oligonucleotide DNA arrays to profile approximately 6000 striatal mRNAs in the R6/2 mouse, a transgenic Huntington's disease (HD) model. We found diminished levels of mRNAs encoding components of the neurotransmitter, calcium and retinoid signaling pathways at both early and late symptomatic time points (6 and 12 weeks of age). We observed similar changes in gene expression in another HD mouse model (N171-82Q). These results demonstrate that mutant huntingtin directly or indirectly reduces the expression of a distinct set of genes involved in signaling pathways known to be critical to striatal neuron function.

Expression of NMDA receptor subunit mRNAs in neurochemically identified projection and interneurons in the human striatum.

N-methyl-D-aspartate (NMDA) receptors are composed of subunits from two families: NR1 and NR2. We used a dual-label in situ hybridization technique to assess the levels of NR1 and NR2A-D messenger ribonucleic acid (mRNA) expressed in projection neurons and interneurons of the human striatum. The neuronal populations were identified with digoxigenin-tagged complementary RNA probes for preproenkephalin (ENK) and substance P (SP) targeted to striatal projection neurons, and somatostatin (SOM), glutamic acid decarboxylase 67 kD (GAD(67)), and choline acetyltransferase (ChAT) targeted to striatal interneurons. Intense NR1 signals were found over all striatal neurons. NR2A signals were high over GAD(67)-positive neurons and intermediate over SP-positive neurons. ENK-positive neurons displayed low NR2A signals, whereas ChAT- and SOM-positive neurons were unlabeled. NR2B signals were intense over all neuronal populations in striatum. Signals for NR2C and NR2D were weak. Only ChAT-positive neurons displayed moderate signals, whereas all other interneurons and projection neurons were unlabeled. Moderate amounts of NR2D signal were detected over SOM- and ChAT-positive neurons; GAD(67)- and SP-positive striatal neurons displayed low and ENK-positive neurons displayed no NR2D hybridization signal. These data suggest that all human striatal neurons have NMDA receptors, but different populations have different subunit compositions that may affect function as well as selective vulnerability.

Expression of alpha-synuclein, parkin, and ubiquitin carboxy-terminal hydrolase L1 mRNA in human brain: genes associated with familial Parkinson's disease.

Mutations in the alpha-synuclein, parkin, and ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) genes have been linked to some cases of familial Parkinson's disease. To provide insight into how these genes may relate to each other and contribute to the pathology of Parkinson's disease, their expression was examined in normal human brain. Tissue sections from multiple regions of 11 normal human brains were hybridized with radiolabeled and digoxygenin-labeled cRNA probes for alpha-synuclein, parkin, and UCH-L1 mRNA. Expression of each of these three genes was predominantly neuronal. Alpha-synuclein and parkin mRNAs were expressed in a restricted number of brain regions, whereas UCH-L1 mRNA was more uniformly expressed throughout brain. The melanin-containing dopamine neurons of the substantia nigra had particularly robust expression. The expression patterns of alpha-synuclein and parkin mRNAs were similar, suggesting that these two proteins may be involved in common pathways contributing to the pathophysiology of Parkinson's disease.

Localization of metabotropic glutamate receptor 7 mRNA and mGluR7a protein in the rat basal ganglia.

Metabotropic glutamate receptors (mGluRs) coupled to G-proteins have important roles in the regulation of basal ganglia function. We have examined the localization of the mGluR7 mRNA and mGluR7a protein in the basal ganglia of the rat. Strong mGluR7 hybridization signals are found in cerebral cortex and striatum, but much less intense signals are present in other components of the basal ganglia. Abundant mGluR7a immunoreactivity was found in striatum, globus pallidus (GP), and substantia nigra pars reticulata (SNr). Examination using confocal microscopy together with dendritic and presynaptic markers as well as studies in lesion models provided evidence for the presence of mGluR7a on presynaptic terminals in all three structures. Electron microscopic studies confirmed the presence of mGluR7a in axon terminals in both the striatum and the GP and also revealed the presence of mGluR7a at postsynaptic sites in both of these regions. Our data demonstrate that mGluR7a is located not only on presynaptic glutamatergic terminals of the corticostriatal pathway, where it may serve as an autoreceptor, but also on terminals of striatopallidal and striatonigral projections, where it may modulate the release of gamma-aminobutyric acid (GABA). The presence of mGluR7 at these multiple sites in the basal ganglia suggests that this receptor has a particularly crucial role in modulating neurotransmitter release in major basal ganglia pathways.

[Huntington chorea. Animal models reveal new hypotheses for pathophysiology and therapy]. / Chorea Huntington. Tiermodelle eröffnen neue Hypothesen zu Pathophysiologie und Therapie.

Huntington's disease (HD) is member of a growing family of neurodegenerative diseases which are caused by a CAG-Triplet expansion in the coding region of their respective genes. The results of the research of the last years is very suggestive of a common pathomechanisms of all these diseases even though their clinical appearance may be quite different. The development of new animal models by transferring the human gene defect into the mouse genome has led to the finding of so-called intranuclear inclusion bodies. This new observation allowed to come closer to solving the problem how this genetic defect causes neurodegeneration. Recent studies on transgenic HD mice could also demonstrate a possible connection between the genetic defect and glutamate exitotoxicity in the neurodegenerative process of HD which had been emphasized by earlier animal models of the disease. Transgenic animal models of HD will have an important impact on the understanding of the disease mechanisms and may contribute to a faster development and testing of new therapeutic approaches.

Altered neurotransmitter receptor expression in transgenic mouse models of Huntington's disease.

Alterations in neurotransmitter receptors are a pathological hallmark of the neurodegeneration seen in Huntington's disease (HD). However, the significance of these alterations has been uncertain, possibly reflecting simply the loss of brain cells. It is not known for certain whether the alteration of neurotransmitter receptors occurs before the onset of symptoms in human HD. Recently we developed transgenic mice that contain a portion of a human HD gene and develop a progressive abnormal neurological phenotype. Neurotransmitter receptors that are altered in HD (receptors for glutamate, dopamine, acetylcholine and adenosine) are decreased in the brain transgenic mice, in some cases before the onset of behavioural or motor symptoms. In transgenic mice, neurotransmitter receptor alterations occur before neuronal death. Further, receptor alterations are selective in that certain receptors, namely N-methyl-D-aspartate and gamma-aminobutyric acid receptors, are unaltered. Finally, receptor decreases are preceded by selective decreases in the corresponding mRNA species, suggesting the altered transcription of specific genes. These results suggest that (i) receptor decreases precede, and therefore might contribute to, the development of clinical symptoms, and (ii) altered transcription of specific genes might be a key pathological mechanism in HD.

Inhibition of caspase-1 slows disease progression in a mouse model of Huntington's disease.

Huntington's disease is an autosomal-dominant progressive neurodegenerative disorder resulting in specific neuronal loss and dysfunction in the striatum and cortex. The disease is universally fatal, with a mean survival following onset of 15-20 years and, at present, there is no effective treatment. The mutation in patients with Huntington's disease is an expanded CAG/polyglutamine repeat in huntingtin, a protein of unknown function with a relative molecular mass of 350,000 (M(r) 350K). The length of the CAG/polyglutamine repeat is inversely correlated with the age of disease onset. The molecular pathways mediating the neuropathology of Huntington's disease are poorly understood. Transgenic mice expressing exon 1 of the human huntingtin gene with an expanded CAG/polyglutamine repeat develop a progressive syndrome with many of the characteristics of human Huntington's disease. Here we demonstrate evidence of caspase-1 activation in the brains of mice and humans with the disease. In this transgenic mouse model of Huntington's disease, expression of a dominant-negative caspase-1 mutant extends survival and delays the appearance of neuronal inclusions, neurotransmitter receptor alterations and onset of symptoms, indicating that caspase-1 is important in the pathogenesis of the disease. In addition, we demonstrate that intracerebroventricular administration of a caspase inhibitor delays disease progression and mortality in the mouse model of Huntington's disease.

Expression of NMDA glutamate receptor subunit mRNAs in neurochemically identified projection and interneurons in the striatum of the rat.

NMDA receptors are composed of proteins from two families: NMDAR1 and NMDAR2. We used quantitative double-label in situ hybridization to examine in rat brain the expression of NMDAR1, NMDAR2A, NMDAR2B, and NMDAR2C mRNA in six neurochemically defined populations of striatal neurons: preproenkephalin (ENK) and preprotachykinin (SP) expressing projection neurons, and somatostatin (SOM), glutamic acid decarboxylase 67 (GAD67), parvalbumin (PARV), and choline acetyltransferase (ChAT) expressing interneurons. NMDAR1 was expressed by all striatal neurons: strongly in ENK, SP, PARV and ChAT neurons, and less intensely in SOM and GAD67 positive cells. NMDAR2A mRNA was present at moderate levels in all striatal neurons except those containing ChAT. Labeling for NMDAR2B was strong in projection neurons and ChAT interneurons, and only moderate in SOM, GAD67 and PARV interneurons. NMDAR2C was scarce in striatal neurons, but a low level signal was detected in GAD67 positive cells. NMDAR2C expression was also observed in small cells not labeled by any of the markers, most likely glia. These data suggest that all striatal neurons have NMDA receptors, but different populations have different subunit compositions which may affect function as well as selective vulnerability.