Pathogenic Neisseria Hitchhike on the Uropod of Human Neutrophils

Polymorphonuclear neutrophils (PMNs) are important components of the human innate immune system and are rapidly recruited at the site of bacterial infection. Despite the effective phagocytic activity of PMNs, Neisseria gonorrhoeae infections are characterized by high survival within PMNs. We reveal a novel type IV pilus-mediated adherence of pathogenic Neisseria to the uropod (the rear) of polarized PMNs. The direct pilus-uropod interaction was visualized by scanning electron microscopy and total internal reflection fluorescence (TIRF) microscopy. We showed that N. meningitidis adhesion to the PMN uropod depended on both pilus-associated proteins PilC1 and PilC2, while N. gonorrhoeae adhesion did not. Bacterial adhesion elicited accumulation of the complement regulator CD46, but not I-domain-containing integrins, beneath the adherent bacterial microcolony. Electrographs and live-cell imaging of PMNs suggested that bacterial adherence to the uropod is followed by internalization into PMNs via the uropod. We also present data showing that pathogenic Neisseria can hitchhike on PMNs to hide from their phagocytic activity as well as to facilitate the spread of the pathogen through the epithelial cell layer

THERMAL PROPERTIES OF SILICA AEROGELS

La densité extrêmement faible des aérogels influence de manière drastique toutes les propriétés thermiques. Comparés à la silice vitreuse, les aérogels montrent une augmentation du transfert radiatif de chaleur ; la conduction par le solide est réduite de deux à trois ordres de grandeurs comme cela est prédit à partir du modèle de diffusion des phonons ; aux basses températures la chaleur spécifique des aérogels est plus grande d'au moins un facteur 10 que pour le verre de silice non poreux. Le transport de chaleur dans les aérogels monolithiques et granulaires est discuté en fonction de la pression du gaz, de la température, de l'émissivité de la courbe limite et de la charge externe.The extremely low density of aerogels drastically influences all thermal properties : Compared to vitreous silica, aerogels show enhanced radiative heat transfer ; the solid conduction is reduced by two to three orders of magnitude as can be predicted from the phonon diffusion model ; at low temperatures the specific heat capacity of aerogels is larger by at least a factor of 10 than for non-porous SiO2- glass. Heat transport in monolithic and granular aerogels is discussed with respect to gas pressure, temperature, boundary emissivity and external load

Electroconvulsive therapy resolves cortical inhibition and manneristic omissions in a chronic catatonic patient

We investigated a patient with severe catatonic schizophrenia (manneristic catatonia according to Karl Leonhard) treated with electroconvulsive therapy (ECT) after pharmacological approaches did not result in any clinical improvement. Before and after nine ECT sessions a double-pulse transcranial magnetic stimulation (TMS) paradigm was used to measure intracortical inhibition (ICI) which has been shown to be reduced in a significant proportion of patients with schizophrenia. Although the patient showed no remission regarding some psychomotor aspects after ECT, we found an increase in ICI and a remarkable clinical improvement of catatonic omissions which might be due to changes in the GABAergic system

Thermal properties of silica aerogels between 1.4 and 330 K

SIGLEAvailable from TIB Hannover: D.Dt.F AC 1000(41,18) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman