[Delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage: prevention, diagnostics and therapy]. / "Delayed cerebral ischemia" nach aneurysmatischer Subarachnoidalblutung : Prävention, Diagnostik und Therapie.

Delayed cerebral ischemia (DCI) is the second most important impacting factor for functional outcome after aneurysmal subarachnoid hemorrhage (SAH) following the initial severity of the bleeding. In contrast to the initial SAH severity the presence and consequences of DCI can be managed with prophylactic and therapeutic interventions. The previous notion of treatment of angiographically observed vasospasm has not been shown to be successful.This article covers prevention, monitoring and therapeutic concepts for patients with SAH with emphasis on the efficacy for DCI and current and ongoing research projects.

Cerebrovascular reactivity and vasospasm after subarachnoid hemorrhage: a pilot study.

The authors performed serial transcranial Doppler (TCD) and carbon dioxide reactivity (CO2R) testing in 20 aneurysmal subarachnoid hemorrhage patients to determine whether impaired cerebrovascular reactivity was associated with symptomatic vasospasm. Symptomatic vasospasm occurred in 9 of 14 patients with abnormal CO2R and in none of 6 patients with preserved reactivity (p = 0.011). Abnormal CO2R preceded the onset of vasospasm in 7 of 9 patients. Abnormal standard TCD testing was not associated with vasospasm.

Transient diffusion-weighted imaging changes in a patient with reversible leukoencephalopathy syndrome.

A 66-year-old man developed a focal status epilepticus and left hemiparesis 4 days after an orthotopic liver transplantation and administration of FK 506. The magnetic resonance image revealed areas of increased signal on diffusion-weighted imaging (DWI) equally distributed to all vascular territories, most of which resolved completely within 2 weeks after discontinuation of FK 506. We conclude that DWI cannot reliably distinguish between reversible and irreversible lesions and that the presence of hyperintense lesions on DWI is not a definitive predictor of poor prognosis in reversible leukoencephalopathy patients.

The inner core region of Yersinia enterocolitica Ye75R (0:3) lipopolysaccharide.

The inner-core region of the lipopolysaccharide of an UDPGalNAc-4-epimerase-deficient mutant of Yersinia enterocolitica 0:3, designated as Ye75R, was investigated using methylation analysis, 1D-13C-NMR and 2D-13C-NMR and 1H-NMR, as well as 31P-NMR, fast-atom-bombardment mass spectrometry (FAB MS) and FAB MS/MS in positive and negative modes. The isolated core heptasaccharide (OS) was composed of 2 units D-glucose, 3 units LD-heptose and 1 unit each of DD-heptose and 3-deoxy-D-manno-octulosonic acid. Methylation analysis indicated that OS was highly branched with terminal location of the two glucoses and the DD-heptose unit, which was partially (to about 40%) phosphorylated at C7. These combined studies allowed us to formulate the structure of the inner core region as shown in Scheme 1. The substitution of the 7-position of the terminally linked DD-heptose unit by phosphate could be recognized by MS characterization of permethylated DD-heptose-7-phosphate (alditol acetate) and the extent of the substitution by the ratio of the two well separated 1H signals of DD-heptose in 500-MHz 1H-NMR. Negative FAB MS of OS also indicated the presence of smaller amounts of two hexasaccharides, differing from OS in lacking either one terminal unit of D-glucose or of the terminal DD-heptose, and additionally of a pentasaccharide lacking two heptosyl units, namely the terminal DD-heptose and and the subterminal LD-heptose. The presence of the smaller oligosaccharides in the OS fraction was also recognized by the methylation analysis.

Differentiation of serological responses to Yersinia enterocolitica serotype O9 and Brucella species by immunoblot or enzyme-linked immunosorbent assay using whole bacteria and Yersinia outer membrane proteins.

Serum samples from 134 patients showing by the microagglutination test serological cross-reactivity between Yersinia enterocolitica serotype O9 and Brucella spp. were analyzed by immunoblot and enzyme-linked immunosorbent assay techniques for the presence of antibodies directed against plasmid-encoded, yersinia-associated outer membrane proteins (OMPs). Since these OMPs are exclusively expressed in pathogenic strains of Yersinia spp., this characteristic was chosen for serological differentiation of infections caused by these bacteria. The presence of antibodies against plasmid-encoded OMPs of pathogenic Yersinia spp. in patient sera appeared to be a suitable means to identify acute or recent infection with Y. enterocolitica serotype O9, whereas the failure to detect such antibodies indicated an acute or recent infection with Brucella spp.

Temperature-dependent incorporation of 4-amino-L-arabinose in lipid A of distinct gram-negative bacteria.

The presence and the relative amount of 4-amino-L-arabinose in lipopolysaccharides of members of the Enterobacteriaceae family and in a single strain of Chromobacterium violaceum has been studied with regard to growth-temperature dependent variations. Changes in the presence and the amount of 4-amino-L-arabinose (4-AA) were observed in almost all cases, but the variations observed were not consistent among different species. While Salmonella minnesota and Proteus mirabilis showed higher levels of incorporation at higher temperatures, the S- and R-forms of Yersinia enterocolitica showed the opposite effect, i.e. only marginal incorporation by growth at 10 degrees C. Chromobacterium violaceum, however, showed no significant alteration in the 4-amino-L-arabinose content when growth either at 14 or at 37 degrees C. DOC-PAGE pattern of isolated lipopolysaccharides showed characteristic profiles indicating that the O-chain-synthesis of distinct Enterobacteriaceae is also differently influenced by changes in growth temperature.

Detection of cross-reacting epitopes on plasmid-encoded outer membrane proteins of enteropathogenic Yersinia by monoclonal antibodies.

Plasmid-positive Yersinia bacteria of different species and different serotypes were analysed with respect to the immunological relationship of two of their plasmid-encoded outer membrane proteins (OMPs) by the immunoblot technique using three monoclonal antibodies (mAb), which were induced against OMPs of Yersinia enterocolitica serotype O:9 bacteria. Evidence is presented that these OMPs display discrete epitopes, which are common to all plasmid-positive Yersinia strains tested, with only one exception, indicating a close structural relationship of the OMPs analysed.

Immunological characterization of Yersinia enterocolitica O:9 and O:3 LPS antigens by monoclonal antibodies.

LPS-specific monoclonal antibodies induced against Y. enterocolitica serotype O:9 bacteria and against Y. enterocolitica O:3 were used in a comparative study to characterize the O:9 and O:3 LPS. Yersinia bacteria grown at 22 degrees C and 37 degrees C and LPS preparations thereof were tested. SDS-PAGE, Western blot analysis and adsorption procedures revealed that LPS of Y. enterocolitica O:9 differed from that of Y. enterocolitica O:3 in: (i) its repeating LPS O-side-chain sugar, (ii) its shorter length of the LPS O-side-chain and (iii) its failure to show temperature-dependent variation in the length of O-side-chains.

Plasmids of Yersinia enterocolitica and Yersinia pseudotuberculosis: analysis with restriction endonucleases.

The plasmids of Yersinia enterocolitica and Yersinia pseudotuberculosis tested differed in regard to the following aspect: there were some of a molecular size of 41 to 47 Mdal which could be correlated with autoagglutination of the host bacteria, and the others with a smaller size of 19 to 34 Mdal that lacked the capacity to code for autoagglutination. Analysis of both types of plasmids with the restriction endonucleases Bam HI, Eco RI and Hind III besides of some similarities revealed also considerable serogroup-specific differences in their DNA fragmentation pattern.

Lung tissue concentrations of cefoperazone.

The following lung tissue concentrations of cefoperazone were found in 20 patients after a 2 g single dose: 45.3-113.3 mg/kg after one hour and 20.5-68.1 mg/kg after two hours. The respective serum levels were measured in parallel determinations for comparison purposes. All determinations were carried out by means of high pressure liquid chromatography. The results suggest that cefoperazone has a rapid and sustained concentration ability in the lung tissue. The drug is therefore suitable for perioperative prophylaxis in lung surgery.

Temperature-dependent changes in the sugar and fatty acid composition of lipopolysaccharides from Yersinia enterocolitica strains.

Yersinia enterocolitica S and R strains change the pattern and the amount of their lipopolysaccharide-linked fatty acids with the respective growth temperature. As described also for other enterobacterial strains, saturated fatty acids are decreased, especially the amount of C14:0, when growth was done at 10 degrees C and unsaturated fatty acids, notably C16:1 (palmitoleic acid), appear, which are present in trace amounts only when bacteria are grown at 40 degrees C. In addition to these changes in the fatty acids, also the amount of O-specific sugars is temperature-dependent. 6-Deoxy-L-altrose which is the only main O-specific sugar in the LPS investigated, amounts to 30-40% (based on LPS dry weight) when grown at 10 degrees C, but only to 13-20% when growth was done at 40 degrees C. The decrease in O-specific material at 40 degrees C can at least partly be explained by the finding of a high number of unsubstituted R core stubs in polyacryl gel-electrophoresis.

Localization of enterobacterial common antigen in Yersinia enterocolitica by the immunoferritin technique.

Rabbits were immunized with the enterobacterial common antigen (ECA)-immunogenic strain Escherichia coli F470. ECA-specific antiserum was obtained by absorbing the resulting antisera with the genetically closely related ECA-negative strain E. coli F1283. These two strains also served as positive and negative controls in the localization study of ECA in Yersinia enterocolitica strain 75, smooth and rough forms (Ye75S and Ye75R), by the indirect immunoferritin technique. Cells of Ye75S grown at 22 degrees C showed no labeling with ferritin after treatment with the ECA-specific antiserum and subsequent ferritin-conjugated goat anti-rabbit antibodies. If the cells were grown at 40 degrees C, however, most of the cells showed weak ferritin labeling. At this higher growth temperature, the lipopolysaccharide of this strain contains less O-specific chains (6-deoxy-L-altrose), as was shown in a previous study. The rough mutant Ye75R, which lacks O-specific chains completely, showed denser labeling with ferritin. These results indicate that ECA on the cell surface of Ye75S is covered by O-specific chains of the lipopolysaccharide if grown at 22 degrees C and is therefore not accessible to ECA antibodies. It becomes accessible, however, when O-chains are lacking (R mutants) or when they are reduced in size or amount (growth at 40 degrees C).

[Sugar composition of the lipopolysaccharide and ultrastructural study of the outer membrane of Yersinia enterocolitica (author's transl)]. / Zuckerzusammensetzung des Lipopolysaccharids und Feinstruktur der äusseren Membran (Zellwand) bei Yersinia enterocolitica.

Phenol-water-extracted lipopolysaccharide (LPS) from Yersinia enterocolitica (strain 75 in smooth form; O-group I), after growth at 10 degrees C, contains approximately 40% (w/w) 6-deoxy-L-altrose. By increasing the cultivation temperature a significant decrease in the O-specific sugar is observed. LPS from cells grown at 40 degrees C contains about 12% 6-deoxy-L-altrose. Thin-section micrographs of cells grown at lower temperatures reveal a distinct layer corresponding to the O-specific side chains of LPS in contrast to cells grown at higher temperatures where a decrease in thickness is observed. It is assumed that this observation is due to the decreasing amount of the O-specific sugar at a higher cultivation temperature. The results obtained by the indirect immunoferritin test indicate that the O-specific polysaccharide layer covers the cell surface completely up to 37 degrees C. However, this layer no longer covers the entire surface of all cells as soon as an incubation temperature of 40 degrees C is applied.

Ultrastructure of lipopolysaccharides of Yersinia enterocolitica, Salmonella typhimurium and Escherichia coli.

The fine structure of isolated lipopolysaccharides (LPS) from the rough and smooth form of an Yersinia enterocolitica strain (Ye 75 R/Ye 75 S) and from smooth forms of Salmonella typhimurium (S 1010) and Escherichia coli (Essen) were examined electron-microscopically by negative staining. Partial denaturation of LPS in Tris-buffer with acid and/or polymyxin B treatment revealed a common structure of strandlike LPS. Electron-microscopically, LPS-strands were found to consist of two identical sub-strands which form a double helix. High resolution electron microscopy permitted the identification of a total of four longitudinal fibrils (diameter approximately 20 A); therefore, each sub-strand consists of two longitudinal fibrils. These results were correlated with those obtained with positive staining procedure and chemical fixation technique. The development of the "double-track"-profile of the outer membrane was interpreted to result from the projection of the helical longitudinal fibrils into the image plane.

On the sugar content of the lipopolysaccharides of the various strains known as Yersinia enterocolitica.

With a single exception among 11 strains, each strain of Y. enterocolitica representing one of the six O-groups possesses, as judged by the sugar composition of its lipopolysaccharides, a particular chemotype. All 14 of the strains examined possessed glucosamine, KDO, two heptoses and glucose. In the most complicated chemotype 10 sugars were demonstrable. Of three Y. enterocolitica strains not included in the 6 O-groups, two had the same chemotype as the representatives of the O-groups IV and VI. Details can be seen in the two tables.