[Tuberculous encephalitis, Landouzy sepsis and Pott's disease: complications after surgery for spinal stenosis]. / Tuberkulöse Enzephalitis, Landouzy-Sepsis und Pott-Krankheit : Komplikationen nach operativer Versorgung einer Spinalkanalstenose.

Tuberculosis is an infectious disease with a decreasing incidence in Germany. In particular, the occurrence of reinfections and possible complications associated with this disease, such as tuberculous meningitis/encephalitis and Landouzy sepsis are rare in industrial countries. In this article the intensive care treatment of a patient who initially underwent surgery for spinal stenosis is reported. Due to recurrent appearance of neurological symptoms with increasing severity and abscess formation in the spine, further surgery was performed. Additionally, the patient developed sepsis and meningitis. At this time an infection with Mycobacterium tuberculosis could be detected in both cerebrospinal fluid and abscess material of the spine suggesting a Landouzy sepsis, tuberculous meningitis/encephalitis and the suspicion of an underlying Pott's disease.

[Epidural cooling. Neuroprotective treatment of thoracoabdominal aortic aneurysms]. / Epidurale Kühlung. Neuroprotektive Versorgung thorakoabdominaler Aortenaneurysmen.

The risk of paraplegia and paraparesis during thoracoabdominal aneurysm surgery still represents a major threat. In 1993, Cambria and coworkers applied for the first time a method of regional spinal cord hypothermia by epidural cooling and significantly diminished the rate of neurological deficits. In this article the first clinical application of this neuroprotective method in Germany will be reported. This neuroprotective method was used in seven patients who underwent elective thoracoabdominal aortic aneurysm repair. The spinal cord was cooled with ice-cold saline via an epidural catheter during surgical repair. Cerebrospinal fluid pressure was measured on-line via a spinal catheter and controlled using active cerebrospinal fluid drainage. Of these seven patients, four showed no postoperative neurological deficit and were released from hospital. The other three patients died in the intra-operative or post-operative phase due to complications other than spinal cord injury arising from pre-existing comorbid conditions. The described method of epidural cooling represents a preliminary experimental method, which might reduce spinal cord injury during surgical repair of thoracoabdominal aneurysms.

RrgA is a pilus-associated adhesin in Streptococcus pneumoniae.

Adherence to host cells is important in microbial colonization of a mucosal surface, and Streptococcus pneumoniae adherence was significantly enhanced by expression of an extracellular pilus composed of three subunits, RrgA, RrgB and RrgC. We sought to determine which subunit(s) confers adherence. Bacteria deficient in RrgA are significantly less adherent than wild-type organisms, while overexpression of RrgA enhances adherence. Recombinant monomeric RrgA binds to respiratory cells, as does RrgC with less affinity, and pre-incubation of epithelial cells with RrgA reduces adherence of wild-type piliated pneumococci. Non-adherent RrgA-negative, RrgB- and RrgC-positive organisms produce pili, suggesting that pilus-mediated adherence is due to expression of RrgA, rather than the pilus backbone itself. In contrast, RrgA-positive strains with disrupted rrgB and rrgC genes exhibit wild-type adherence despite failure to produce pili by Western blot or immunoelectron microscopy. The density of bacteria colonizing the upper respiratory tract of mice inoculated with piliated RrgA-negative pneumococci was significantly less compared with wild-type; in contrast, non-piliated pneumococci expressing non-polymeric RrgA had similar numbers of bacteria in the nasopharynx as piliated wild-type bacteria. These data suggest that RrgA is central in pilus-mediated adherence and disease, even in the absence of polymeric pilus production.

Bradykinin-stimulated Cl- secretion in T84 cells. Role of Ca2+-activated hSK4-like K+ channels.

Bradykinin (BK)-stimulated colonic Cl- secretion was studied in T84 colonic adenocarcinoma cells by measuring BK (50 nM)-evoked changes in cytosolic free [Ca2+] ([Ca2+]i), membrane conductance and transepithelial ion transport. In T84 cells grown on impermeable supports, BK stimulated a transient increase in [Ca2+]i as assessed by fura-2 ratio imaging. In cell-attached, patch-clamp recordings, BK transiently activated low-conductance K channels. These channels were activated/inactivated reversibly in inside-out patches by switching [Ca2+]i in the bath between 30 nM and 100 nM. Excised channels recorded with 160 mM [K+] in bath and pipette exhibited an inwardly rectifying current/voltage-relation, conductances of 10+/-1 pS and 34+/-4 pS (n=10) at positive and negative voltages, respectively, and a 15-fold lower permeability for Na+ than for K+. The mean open probability of these channels did not depend on voltage but increased with increasing [Ca2+]i with an apparent concentration for a half-maximal response (EC50) of 110 nM, resembling that of hSK4 K+ channels. Application of the reverse transcriptase-polymerase chain reaction technique showed hSK4 messenger ribonucleic acid (mRNA) to be expressed in T84 cells. Macroscopic currents in T84 cells showed a similar dependence on [Ca2+]i. Whole cell conductance (in nS/10pF) increased from 0.5+/-0. 1 (n=6) at 10 nM [Ca2+]i in the pipette solution to 1.5+/-0.2 (n=7) at 100 nM, and to 2.0+/-0.5 (n=7) at 1 microM due to activation of a K+ conductance. In Ussing-chambered T84 monolayers grown on filters, BK did not evoke a short-circuit current (Isc). When, however, the monolayers were pre-stimulated by forskolin (1 microM), BK further enhanced Cl-secretion (DeltaIsc=21+/-5 microA/cm2, n=10) transiently and biphasically. In conclusion, BK enhances cyclic adenosine monophosphate-stimulated Cl- secretion in T84 cells, probably via basolateral, Ca2+-liganded activation of low-conductance hSK4-type K+ channels.

Epithelial nephrogenesis.

The metanephric, or definitive, kidney forms as a result of inductive processes between tissues of two distinct embryologic origins, the metanephric mesenchymal blastema and the ureteric bud. After inductive signalling between these primordial tissues, mesenchymal cells aggregate next to the branching ureteric bud tip, convert to epithelial cells and differentiate into the diverse cell populations of the nephron. The ureteric bud enters branching morphogenesis and gives rise to the collecting duct system. Nephrogenesis has become a target system by which to study developmental processes including embryonic inductive interactions, mesenchyme-to-epithelium conversion, cell lineage pathways, epithelial cell polarization, branching morphogenesis and spatio-temporal expression of transcription factors. This review summarizes data on cellular and extracellular events during epithelial metanephrogenesis.