快动眼睡眠行为异常与钾通道抗体相关边缘脑炎

本医疗中心登记的6例非副肿瘤性边缘脑炎患者与电压门控钾通道抗体相关,其中5例男患者同时表现出快动眼睡眠行为异常(R BD)和电压门控钾通道抗体相关边缘脑炎发作。3例患者经免疫抑制治疗后的R BD和边缘综合征同时消退,2例患者的边缘综合征部分缓解而RBD持续存在。本研究结果表     

Hepatic encephalopathy secondary to porto-systemic shunt satisfactorily treated with interventionist radiology

Hepatic encephalopathy is a reversible state of altered cognition that may occur in patients with acute or chronic liver disease or porto-systemic shunt, and in which known neurological or psychiatric signs may develop. Nitrogenated substances from intestinal digestion reach the brain without being cleared by their passage through the liver due to the presence of porto-systemic shunt. We report two cases of patients with porto-systemic shunt diagnosed with recurrent chronic hepatic encephalopathy refractory to conventional medical treatment. They were satisfactorily treated with shunt embolization using interventionist radiology techniques.     

EFNS Guidelines on diagnosis and treatment of brain metastases: report of an EFNS Task Force

The objectives have been to establish evidence-based guidelines and identify controversies regarding the management of patients with brain metastases. The collection of scientific data was obtained by consulting the Cochrane Library, bibliographic databases, overview papers and previous guidelines from scientific societies and organizations. A tissue diagnosis is necessary when the primary tumor is unknown or the aspect on computed tomography/magnetic resonance imaging is atypical. Dexamethasone is the corticosteroid of choice for cerebral edema. Anticonvulsants should not be prescribed prophylactically. Surgery should be considered in patients with up to three brain metastases, being effective in prolonging survival when the systemic disease is absent/controlled and the performance status is high. Stereotactic radiosurgery should be considered in patients with metastases of 3–3.5 cm of maximum diameter. Whole-brain radiotherapy (WBRT) after surgery or radiosurgery is debated: in case of absent/controlled systemic cancer and Karnofsky Performance score of 70 or more, one can either withhold initial WBRT or deliver early WBRT with conventional fractionation to avoid late neurotoxicity. WBRT alone is the treatment of choice for patients with single or multiple brain metastases not amenable to surgery or radiosurgery. Chemotherapy may be the initial treatment for patients with brain metastases from chemosensitive tumors.     

Role of DAT‐SPECT in the diagnostic work up of Parkinsonism

The diagnosis of idiopathic Parkinson's disease (PD) can be achieved with high degrees of accuracy in cases with full expression of classical clinical features. However, diagnostic uncertainty remains in early disease with subtle or ambiguous signs. Functional imaging has been suggested to increase the diagnostic yield in parkinsonian syndromes with uncertain clinical classification. Loss of striatal dopamine nerve terminal function, a hallmark of neurodegenerative Parkinsonism, is strongly related to decreases of dopamine transporter (DAT) density, which can be measured by single photon emission computed tomography (SPECT). The use of DAT‐SPECT facilitates the differential diagnosis in patients with isolated tremor symptoms not fulfilling PD or essential tremor criteria, drug‐induced, psychogenic and vascular Parkinsonism as well as dementia when associated with Parkinsonism. This review addresses the value of DAT‐SPECT in early differential diagnosis, and its potential as a screening tool for subjects at risk of developing PD as well as issues around the assessment of disease progression. © 2007 Movement Disorder Society     

Niflumic acid-induced increase in potassium currents in frog motor nerve terminals: effects on transmitter release

The actions of the nonsteroidal antiinflammatory drug niflumic acid were studied on frog neuromuscular preparations by conventional electrophysiological techniques. Niflumic acid reduced the amplitude and increased the latency of endplate potentials in a concentration-dependent manner. Neuromuscular junctions pretreated with niflumic acid (0.05–0.5 mM) showed much less depression than control when they were stimulated with trains of impulses. Inhibition of acetylcholine release was reverted by raising the extracellular Ca²⁺ concentration but not by simply washing out the preparations with niflumic acid-free solutions. Pretreatment with indomethacin (0.1 mM), another nonsteroidal antiinflamatory drug, did not affect the niflumic acid-induced inhibition of evoked responses. Niflumic acid (0.1 mM) did not change the amplitude of miniature endplate potentials and had a dual action on the frequency of miniatures: it decreased their frequency at 0.1 mM whereas it produced an enormous increase in the rate of spontaneous discharge at 0.5 mM. Niflumic acid (0.1–1 mM) reversibly increased the amplitude and affected the kinetics of presynaptic voltage-activated K⁺ current and Ca²⁺-activated K⁺ current in a concentration-dependent manner. Niflumic acid (0.1–1 mM) irreversibly decreased the amplitude and reversibly affected the kinetics of the nodal Na⁺ current. Indomethacin (0.1 mM) had no effect on presynaptic currents. In conclusion, niflumic acid reduces acetylcholine release by increasing presynaptic K⁺ currents. This may shorten the depolarizing phase of the presynaptic action potential and may reduce the entry of Ca²⁺ with each impulse.     

Brain mapping analysis in patients with hepatic encephalopathy

Summary Topographical analysis of cerebral electrical activity was performed in 44 patients with hepatic encephalopathy. These patients were classified in 5 groups according to clinical criteria. Eight healthy subjects were used as a control group. All were studied in an awake, eyes closed, condition and some [Control Group (CG), Group 0 (G0), Group 1 (G1) and Group 2 (G2)] also in an awake, eyes open, condition. The awake, eyes closed, maps showed marked differences in the power spectral density (PSD) of the different bands, when comparing normal subjects with patients with several degrees of hepatic encephalopathy. These differences were related to the degree of clinical involvement, mainly in the alpha and delta PSD bands. The combination of a decreased alpha PSD, increased delta PSD, and decreased mean dominant frequency (MDF) allowed a clear discrimination between the different clinical groups. The differences observed between awake, eyes closed, and awake, eyes open, conditions were especially helpful to discriminate between CG subjects and G0, G1 and G2 patients.     

Autosomal genetics and Y-chromosome haplogroup L1b-M317 reveal Mount Lebanon Maronites as a persistently non-emigrating population

Currently, there are 18 different religious communities living in Lebanon. While evolving primarily within Lebanon, these communities show a level of local isolation as demonstrated previously from their Y-haplogroup distributions. In order to trace the origins and migratory patterns that may have led to the genetic isolation and autosomal clustering in some of these communities we analyzed Y-chromosome STR and SNP sample data from 6327 individuals, in addition to whole genome autosomal sample data from 609 individuals, from Mount Lebanon and other surrounding communities. We observed Y chromosome L1b Levantine STR branching that occurred around 5000 years ago. Autosomal DNA analyses suggest that the North Lebanese Mountain Maronite community possesses an ancestral Fertile Crescent genetic component distinct from other populations in the region. We suggest that the Levantine L1b group split from the Caucasus ancestral group around 7300 years ago and migrated to the Levant. This event was distinct from the earlier expansions from the Caucasus region that contributed to the wider Levantine populations. Differential cultural adaption by populations from the North Lebanese Mountains are clearly aligned with the L1b haplotype STR haplogroup clusters, indicating pre-existing and persistent cultural barriers marked by the transmission of L1b lineages. Our findings highlight the value of uniparental haplogroups and STR haplotype data for elucidating biosocial events among these populations.Subject terms: Population genetics, Computational biology and bioinformatics     

Heterogeneity of structural abnormalities in the 7q31.3 approximately q34 region in myeloid malignancies

Abnormalities in the long arm of chromosome 7 are a frequent chromosomal aberration in myeloid disorders. Most studies have focused on the analysis of del(7q), demonstrating the presence of several minimal deleted regions in 7q22 approximately q31. By contrast, few studies in myeloid disorders have been devoted to the analysis of translocations, either balanced or unbalanced, involving 7q. In this study, we used fluorescence in situ hybridization (FISH) to characterize the 7q31.3 approximately q34 region (markers D7S480-D7S2227) in patients with deletion or translocation of 7q. A total of 910 cases of myeloid disorders were studied by conventional cytogenetics. Fifty-eight (6%) patients had structural aberrations of 7q. FISH studies were carried out in the 27 patients with involvement of 7q31 approximately q34: 14 cases had an acute myelogenous leukemia and 13 cases had a myelodysplastic syndrome. FISH analysis revealed the existence of high complexity in the 7q31.3 approximately q34 region in patients with unbalanced translocations. No breakpoints in 7q31.3 approximately q34 were found in the cases with deletion or balanced translocation. Nevertheless, studies of unbalanced translocations showed several breakpoints in markers D7S480-D7S2227, which delineate a commonly altered region. The complexity of 7q rearrangements suggests that a synergy of different genetic factors, rather than the alteration of a single tumor suppressor gene, could be involved in the pathogenesis of del(7q) in myeloid disorders.     

The gene DIS2S1 is essential in Saccharomyces cerevisiae and is involved in glycogen phosphorylase activation

Summary S. cerevisiae gene DIS2S1, which codes for a protein very similar to the catalytic subunit of mammalian protein phosphatase 1, was disrupted in vitro. Diploid yeast cells were transformed and sporulated. Tetrad analysis demonstrated that disruption of DIS2S1 is lethal for the cell. Glycogen phosphorylase a and glycogen synthase activity ratio were measured in diploids carrying a disrupted allele of the gene. Phosphorylase was dramatically activated in mutant cells but, under the same conditions, glycogen synthase activity was essentially identical in both mutant and wild-type cells.