Participation of low-threshold Ca2+ spike in the Purkinje cells complex spike

In Purkinje cells from cerebellar slice cultures, low-threshold Ca spike (LTS) gives rise to complex bursts in the soma that resemble the complex spike induced by climbing fibers stimulation. We show that LTS is reduced by T-type and R-type Ca channel blockers (SNX-482, nickel, or mibefradil). We propose that LTS is generated by openings of T-type Ca channels (alpha-1G and/or alpha-1I subunits) and R-type Ca channels (alpha-1E subunit isoforms with a weak sensitivity to SNX-482 and to nickel). Using mibefradil we show that climbing fiber stimulation activates LTS, which contributes to the shape of the response. This Ca entry may be involved in Ca-dependent synaptic plasticity of the parallel fiber input induced by climbing fiber activation.     

Recombinant expression of the beta-subunit of HLA-DR10 for the selection of novel lymphoma targeting molecules

Selective high-affinity ligands (SHALs) were selected as substitutes for monoclonal antibodies (mAbs) to deliver radioisotopes to malignant tumors. Because a SHAL (5 KD) is considerably smaller in comparison to an antibody (150 KD), a significant therapeutic index (TI) enhancement for radioimmunotherapy (RIT) is anticipated. The antibody-antigen (Ab-Ag) model system chosen for the development of SHALs consists of Lym-1, a MAb with proven selectivity in non-Hodgkin's lymphoma (NHL) patients and its well-characterized Ag, the beta subunit of HLA DR10. Whereas Lym-1 is readily available, the subunit of HLA-DR10 is not. Native, heterodimeric (alpha and beta subunits) HLA-DR10 can be purified from Raji cells, which are known to overexpress this Ag. Inconsistent homogeneity between preparations of HLA-DR10 solubilized in the presence of detergents prompted us to express a recombinant form of the beta subunit of HLA-DR10 in Escherichia coli. Negligible production yields (相似文献   

Region-specific differentiation of embryonic stem cell-derived neural progenitor transplants into the adult mouse hippocampus following seizures

Embryonic stem (ES) cells can generate neural progenitors and neurons in vitro and incorporate into the adult central nervous system (CNS) following transplantation, suggesting their therapeutic potential for treating neurological disorders. However, our understanding of the conditions that direct ES-derived neural progenitor (ESNP) migration and differentiation within different regions of the adult CNS is incomplete. Rodents treated with the chemoconvulsant kainic acid (KA) experience seizures and display hippocampal sclerosis, as well as enhanced hippocampal neurogenesis, similar to pathological findings in patients with temporal lobe epilepsy (TLE). To examine the potential for ESNPs to incorporate into the adult hippocampus and differentiate into hippocampal neurons or glia following seizure-induced damage, we compared the fates of ESNPs after they were transplanted into the CA3 region or fimbria 1 week following KA-induced seizures. After 4-8 weeks, ESNPs grafted into the CA3 region had migrated to the dentate gyrus (DG), where a small subset adopted neural stem cell fates and continued to proliferate, based on bromodeoxyuridine uptake. Others differentiated into neuroblasts or dentate granule neurons. In contrast, most ESNPs transplanted into the fimbria migrated extensively along existing fiber tracts and differentiated into oligodendrocytes or astrocytes. Hippocampal grafts in mice not subjected to seizures displayed a marked tendency to form tumors, and this effect was more pronounced in the DG than in the fimbria. Taken together, these data suggest that seizures induce molecular changes in the CA3 region and DG that promote region-specific neural differentiation and suppress tumor formation.     

Genotyping: a new application for the spent dialysate in peritoneal dialysis.

BACKGROUND: The dialysate of patients on peritoneal dialysis (PD) is used to determine the concentration of growth factors and cytokines, and as a source of resident peritoneal cells for subsequent culture experiments. We hypothesized that the cells contained in spent dialysate samples obtained at the time of the peritoneal equilibration test (PET) and subsequently stored may represent a source of DNA from a given PD patient. METHODS: We characterized a protocol of DNA extraction from dialysates obtained in PD patients after a long dwell during the initial PET and kept frozen up to several years. After amplification of the source DNA by strand displacement using the bacteriophage phi 29 DNA polymerase, we performed polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis for the Glu298Asp polymorphism of ENOS to demonstrate the suitability of the extracted DNA for genotyping. RESULTS: A significant amount of DNA (mean yield 12 microg/ml dialysate) was extracted from frozen dialysate samples. The extraction yield was not influenced by the duration of storage at -20 degrees C. Following amplification, the DNA extracted from the dialysate was used successfully for genotyping the Glu298Asp polymorphism of ENOS, as demonstrated by parallel analyses using DNA extracted from the peripheral blood and sequencing. CONCLUSIONS: These results demonstrate that the dialysis effluent obtained at the time of the initial PET and stored at -20 degrees C is a reliable source of DNA that can be used subsequently for PCR amplification, RFLP analysis and sequencing.     

Neuroprotective Strategies to Avert Seizure-Induced Neurodegeneration in Epilepsy

Summary:  Neurodegeneration in limbic circuits is a hallmark feature of chronic temporal lobe epilepsy (TLE). Studies in experimental animal models and human patients indicate that seizure-induced neuronal injury involves some active, as well as passive cell death processes. Experimental approaches that inhibit active steps in cell death programs have been shown to reduce neuronal cell death and sclerosis, but not to prevent epileptogenesis in animal models of TLE. These findings suggest that we need additional research using both animal models and brain slices from human patients to understand the pathological mechanisms underlying seizure generation. Such comparative studies will also aid in evaluating the potential therapeutic value of inhibiting cell death in seizure disorders.     

Of heliotropes and hemorrhoids

During the Middle Ages, an integral part of the therapy for certain ailments included supplication to “patron” saints for possible divine intervention. Through legends surrounding his life, St. Fiacre, a 7th century Irish monk, has become the patron saint for hemorrhoid sufferers.     

Clinical implications of systemic inflammatory response syndrome following thoracic aortic stent-graft placement.

PURPOSE: To quantify inflammatory markers in a large cohort of patients undergoing thoracic endovascular aortic repair (TEVAR) and investigate if profound biomarker elevations may be predictors of postprocedural death. METHODS: We analyzed data from 103 patients (70 men; mean age 64.5+/-11.2 years, range 22-83) undergoing TEVAR between July 1999 and December 2006. Baseline as well as at least 3 serial measurements of C-reactive protein (CRP), fibrinogen, white blood cell (WBC) count, and D-dimers were performed within the first 20 days after TEVAR. RESULTS: Compared with baseline, all inflammatory biomarker levels rose significantly. WBC peaked 2 days after the procedure, whereas CRP, fibrinogen, and D-dimers showed a sustained elevation up to 20 days after TEVAR. Inflammatory responses were more pronounced in patients with acute aortic pathology compared with chronic aortic diseases. There was evidence of greater increase in biomarkers with an increasing number of stent-grafts implanted. Kaplan-Meier analysis suggested that increasing maximum D-dimer values postoperatively were associated with decreased survival after TEVAR (p=0.036) in a subset of patients; however, multivariate analysis failed to identify postinterventional biomarker elevation as independent predictor of in-hospital death. CONCLUSION: Postprocedural inflammatory responses characterized by elevations of CRP, fibrinogen, D-dimers, and WBC are observed in all patients undergoing TEVAR. Our data indicate that this response is more pronounced in patients with acute aortic pathology and those receiving >1 stent-graft.     

Continuous Circulation of Yellow Fever among Rural Populations in the Central African Republic

Yellow fever remains a public-health threat in remote regions of Africa. Here, we report the identification and genetic characterisation of one yellow-fever case observed during the investigation of a cluster of nine suspected haemorrhagic fever cases in a village in the Central African Republic. Samples were tested using real-time RT-PCR targeting the main African haemorrhagic fever viruses. Following negative results, we attempted virus isolation on VERO E6 cells and new-born mice and rescreened the samples using rRT-PCR. The whole viral genome was sequenced using an Illumina NovaSeq 6000 sequencer. Yellow-fever virus (YFV) was isolated from one woman who reported farming activities in a forest setting several days before disease onset. Phylogenetic analysis shows that this strain belongs to the East–Central African YFV genotype, with an estimated emergence some 63 years ago. Finally, five unique amino-acid changes are present in the capsid, envelop, NS1A, NS3, and NS4B proteins. More efforts are required to control yellow-fever re-emergence in resource-limited settings.     

Lipophilic cationic porphyrins as photodynamic sensitisers—Synthesis and structure–activity relationships

A convenient synthesis of a range of phosphorous and nitrogen centred lipophilic cationic porphyrins is described. In vitro assays for photodynamic activity against human colorectal adenocarcinoma cells (HT-29) reveal significant differences based on substituents around the cation centres.