AMPA/kainate receptor activation inhibits neuronal delayed rectifier K+ current via Na+ entry in rat cortical neurons

In the present study we evaluated the modulation of neuronal delayed rectifier K+ current (IK) by activation of ionotropic glutamate receptors. In whole-cell voltage-clamp experiments, an external application of 10-100 microM kainate suppressed the amplitude of IK following an inward shift of holding current. The effect of kainate on IK was eliminated by CN QX, an AMPA/kainate receptor antagonist, indicating that the receptor-mediated cation entry caused IK suppression. When external Na+ was completely replaced by equimolar choline+ or N-methyl-D-glucamine, kainate-induced IK suppression was abolished. Our results suggest that in cultured rat cortical neurons, AMPA/kainate receptor activation leads to an intracellular Na+ increase which blocks delayed rectifier K+ channels. This contributes to feed-forward excitation of neuronal cells in glutaminergic responses.     

Clinical usefulness of 3-D CT endoscopic imaging of cerebral aneurysms

Chronic granulomatous disease (CGD) of childhood is a rare inherited disease in which phagocytic cells fail to produce the normal respiratory burst in response to infectious stimuli, leaving the patient particularly susceptible to infections with bacteria and fungi that produce catalase. Between 1988 and 1993 at the NIH, 58 pulmonary cytology specimens were obtained on 24 CGD patients. The number of specimens per patient ranged from one to 13 with an average 2.4. The 58 specimens included: 33 bronchoalveolar lavages; one bronchial brushing; 20 lung or pleural mass fine-needle aspirates; three pleural fluids, and one sputum. Two lung aspirates with insufficient material, five bronchoalveolar lavages performed post-treatment to confirm clinical resolution of disease, and two bronchoalveolar lavages not submitted for culture were excluded from further analysis. Of the 49 remaining specimens obtained from patients clinically suspected of having a pulmonary infection, cytology demonstrated a pathogenic organism in nine (18%). Microbiologic cultures were positive in 19/49 (39%). Cytology identified fungus in 8/13 (62%) of documented fungal infections, including four cases where microbiology was negative. Bacterial and mixed bacterial/fungal infections were usually not detected by cytology even with appropriate strains. No organisms were identified by cytology in the four cases of nocardia or the three cases of pseudomonas infection. The combination of cytology and microbiology provided the greatest diagnostic sensitivity, yielding a diagnosis in 22/49 cases (45%). Of the 27 cases with negative cytology and microbiology, an infectious agent was identified in eight upon submission of additional material: three cytology specimens and five tissue specimens. In the remaining 19 cases, no organisms were identified, however, the patients were treated presumptively. Characteristic pathologic features of granulomatous inflammation, necrosis, and giant cells were present in fine-needle aspirates, often when on organisms could be identified, but were not seen in other types of respiratory specimens.     

Effects of GABA on spontaneous [Ca2+]c dynamics and electrical properties of rat adrenal chromaffin cells

We studied whether the receptor (R) for C5a could be exploited to deliver the radiolabeled ligand into U937 cells. A dose-response for uptake of 125I-C5a was demonstrated. Incorporation of [3H]leucine by unstimulated or gamma-INF-stimulated U937 cells treated with 125I-C5a, was significantly lower compared with cells treated with 125I alone. Trypan blue exclusion experiments indicated that gamma-INF stimulated cells incubated with 125I-C5a were less viable than cells exposed to 125I or C5a alone. The results suggest that 125I-C5a is internalized into myeloid cells via C5a-R and is more cytotoxic in vitro than the radiolabel alone, but only at/above a specific activity of 4 microCi/microg.     

Measured activation cross sections below 10 MeV for the V(n, p)Ti and V(n, α)Sc reactions

The activation method is used to measure cross sections for the ⁵¹V(n, p)⁵¹Ti reaction from E_n = 2.856 to 9.267 MeV and for the ⁵¹V(n, α)⁴⁸Sc reaction from 5.515 to 9.567 MeV. Both measurements utilize ENDF/B-V evaluated neutron-induced fission cross sections of ²³⁸U as a standard. The experimental results from this work are compared with corresponding ENDF/B-V evaluated cross sections for V and substantial differences are evident. The most significant difference is a tendency for the measured values to exceed evaluated ones by as much as 50% in the vicinity of 8 MeV.     

Measured activation cross sections below 10 MeV for the 51V(n,p)51Ti and 51V(n, α)48Sc reactions

The activation method is used to measure cross sections for the ⁵¹V(n, p)⁵¹Ti reaction from E_n = 2.856 to 9.267 MeV and for the ⁵¹V(n, α)⁴⁸Sc reaction from 5.515 to 9.567 MeV. Both measurements utilize ENDF/B-V evaluated neutron-induced fission cross sections of ²³⁸U as a standard. The experimental results from this work are compared with corresponding ENDF/B-V evaluated cross sections for V and substantial differences are evident. The most significant difference is a tendency for the measured values to exceed evaluated ones by as much as 50% in the vicinity of 8 MeV.     

Rechargeable solid electrolyte cells with a copper ion conductor,Rb4Cu16I7−δCl13+δ, and a titanium disulphide cathode

A rechargeable solid electrolyte cell has been developed using a high copper-ion-conductivity solid electrolyte, Rb₄Cu₁₆I_7–Cl₁₃₊, a copper anode, and an intercalation cathode, TiS₂. The open-circuit voltage was 0.59 V at 25° C. The cell yielded a current of several tens of microamperes at room temperature without appreciable polarization. The cell could be submitted to one hundred or more charge-discharge cycles without showing appreciable deterioration.