Changes in phosphorylated heat-shock protein 27 in response to acute ureteral obstruction in rats.

AIM: In vivo, renal medullary interstitial cells (RMICs) and collecting duct principal cells (mpkCCD cells) are subjected to inflammatory, oxidative and mechanical stress as a result of unilateral ureteral obstruction (UUO). Because heat-shock protein (HSP) 27 and HSP70 are induced by cellular stresses and play a role in cytoprotection, we hypothesized that HSP27 and HSP70 are increased in rats subjected to acute UUO and in RMICs and mpkCCD cells exposed to inflammatory, oxidative or mechanical stress. METHODS: Rats were subjected to acute UUO for 6 h and 12 h. To examine the expression of HSP27, phosphorylated HSP27 (pHSP27) and HSP70 in response to inflammatory, oxidative and mechanical stress in vitro, we exposed RMICs and mpkCCD cells to interleukin 1ß (IL-1ß), hydrogen peroxide (H2 O2 ), and stretch stimulation over time. RESULTS: The phosphorylated form of HSP27 (pHSP27) was increased in the renal inner medulla (IM) after 6-h and 12-h UUO, while HSP27 and HSP70 were unchanged. Furthermore, after 6 h and 12 h of UUO, the expression of inflammatory (IL-1ß) and oxidative [haem oxygenase 1 (HO-1)] markers was induced. Exposure to inflammatory, oxidative and mechanical stress changed HSP27 and pHSP27 expression in RMICs but not in mpkCCD cells, while HSP70 was not affected by any of the stress conditions. Exposure of RMICs to oxidative and mechanical stress induced HSP27 phosphorylation via a p38-dependent mechanism. CONCLUSION: These data demonstrate that, in response to acute UUO, different forms of cellular stresses modulate HSP27 expression and phosphorylation in RMICs. This may affect the ability of renal cells to mount an effective cytoprotective response.

FDG PET/CT in cancer therapy monitoring: computer-assisted analysis of baseline together with up to two follow-ups.

OBJECTIVES: We developed and tested a software tool for computer-assisted analysis of FDG-PET/CT in cancer therapy monitoring. The tool provides automatic semi-quantitative analysis of a baseline scan together with up to two follow-up scans (standardized uptake values, glycolytic volume). The tool also supports visual analysis by local spatial registration which allows display of tumor lesions with the same orientation in all scans. The tool's stability and accuracy was tested at typical everyday image quality. PATIENTS, METHODS: Ten unselected cancer patients in whom three FDG PET/CT scans had been performed were included. A total of 18 lesions were analyzed. RESULTS: Automatic lesion tracking worked properly in all lesions but one. In this lesion local coregistration had to be adjusted manually which, however, is easily performed with the tool. Semi-automatic lesion segmentation and fully automatic semi-quantitative analysis worked properly in all cases. Computer-assisted analysis was significantly less time consuming than manual analysis. CONCLUSIONS: The novel software tool appears useful for analysis of FDG-PET/CT in cancer therapy monitoring in clinical routine patient care.

Motion compensated projection reconstruction.

Over recent years, MRI has shown the capability for real-time applications. Although the acquisition times of fast MRI methods have been reduced significantly, patient motion during a magnetic resonance imaging (MRI) examination still causes artifacts in the image. In this paper, the effects of motion in MRI using a radial acquisition scheme are examined. It is shown that motion can be estimated without the use of additional measurement, based on the acquired projections only. A new reconstruction technique is introduced that integrates a motion compensation algorithm into the MR-reconstruction process, resulting in a significant reduction of blurring artifacts in the reconstructed images. The proposed method is applied to different kinds of motion such as kinetic joint studies.

Fast 1H spectroscopic imaging using a multi-element head-coil array.

Fast proton magnetic resonance spectroscopic imaging (MRSI) using a multi-element head-coil array is examined with respect to three aspects: the coil design, the use of an appropriate signal combination method, and the design of the MRSI pulse sequence itself. An eight-element head-coil array has been developed to increase the signal-to-noise ratio (SNR) of MRSI in the human brain. The flexible wraparound design optimally fits different head sizes and thus provides high sensitivity. The signal combination of the individual coil elements is based on the approach proposed by Roemer et al. (Magn. Reson. Med. 16, 192 (1990)). An additional short prescan is performed to provide a good estimate of the complex coil sensitivity profiles, which are used in the signal combination procedure to correct the spectroscopic imaging data for the spatially varying intensity. The use of coil arrays in MRSI has some effect on the requirements for both water and lipid suppression. These techniques and a MRSI pulse sequence that provides a high spectroscopic resolution are described and discussed. Experimental results at 1.5 T show that metabolite maps of N-acetylaspartate (NAA), choline (Cho), phosphocreatine (PCr)/creatine (Cr) can be obtained within a 5-min acquisition time.

Modulatory function on autologous myeloid progenitor cells of clonal T-lymphocytes following autologous bone marrow transplantation.

We have studied the regulatory capacity of clonal T-lymphocytes from patients undergoing autologous bone marrow transplantation (ABMT) on the generation of CFU-GM from their harvest marrow preparations. To this end, T-lymphocytes from peripheral blood from 5 patients undergoing ABMT isolated 10 d before and 7, 14 and 28 d post-ABMT were placed in limiting dilution conditions (384 wells for each patient at each time point) and polyclonally stimulated. From more than 1600 wells with growth from the 5 patients, preparations from more than 900 wells could be expanded (range between patients 33-452) and identified by immunophenotyping (IP) and flow cytometry (FCM) by their exclusive expression of CD4 or CD8. This was significantly fewer than seen in normal donors, especially so at d 7 and 14 post-ABMT The ratio between CD4+ and CD8+ clones varied between 0.6 and 2.8 (median 1.3) and was significantly lower in the patients compared to normal donors (median 3.1; range 3.0-6.5). When the clonal T-cell preparations were co-cultured with autologous bone marrow cells obtained at the time of harvest and depleted for T-lymphocytes, the vast majority of both CD4+ and CD8+ clones exerted a clear enhancement on the CFU-GM growth with no relation to time of blood sampling in its the magnitude. Moreover, a trend seen in the normal donors towards CD4+ clones being more effective in this enhancement was not observed in ABMT patients. We conclude that clonal T-cells from ABMT patients, irrespective of their phenotype and time of isolation, exert an enhancement on the growth of autologous CFU-GM, which is equal to that seen in normal donors.

Delineation of erythropoiesis in normal and malignant bone marrow using monoclonal antibody AS-E1 directed against transferrin receptors (CD71).

We have delineated the erythropoietic compartment in normal and malignant bone marrow (BM) by using the monoclonal antibody (mAb) AS-E1 directed against the transferrin receptor by flow cytometric (FCM) analysis. In normal BM we found a bimodal expression in antigen density with a minor subset (approximately 3%) expressing AS-E1high and a larger subset (approximately 15%) expressing AS-E1low. By fluorescence activated cell sorting, morphological examination of smears stained by immunocytochemistry and by BFU-E assays the AS-E1high fraction was shown to contain cells of erythroid origin (proerythroblasts, basophilic erythroblasts and polychromatic erythroblasts), whereas the AS-E1low fraction consisted mainly of promyelocytes and myelocytes. In patients with malignant hematological disorders we found a more pronounced heterogeneity in the density and the degree of AS-E1low expression compared to normal BM, and to further characterize the AS-E1low cells in patients and to exclude that this broad reactivity interfered with the identification of the AS-E1high cells, we employed triple-color FCM assays with mAbs directed against the myeloid surface markers CD13 and CD66 in addition to AS-E1. In all patients we found that 80-90% of the AS-E1low cells co-expressed CD13 and/or CD66 and thus were of myeloid origin. Finally, we evaluated 2 methods for determination of the AS-E1high subset and found an assay involving forward light scatter and logAS-E1 density to be sufficient. We conclude that AS-E1high is a valid FCM marker for the normal erythropoiesis.

Effect of antibiotics eliminated by first order kinetics.

We wanted to simulate the conditions within the body where bacteria are exposed to antibiotics at concentrations which diminish exponentially and thus do not remain constant as in the usual test systems for determination of the minimum inhibitory or bactericidal concentrations (MIC, MBC). For this purpose we employed a model with a glass chamber containing a constant volume of culture which was supplied continuously with medium at a constant rate. We studied the pattern of bacterial response using a series of bactericidal and bacteriostatic agents added to the system at various multiples of the MIC of several bacterial strains, and using different rates of elimination of the antibacterial agent. Strains of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Streptococcus pyogenes were exposed to amoxicillin, ampicillin, benzylpenicillin, carbenicillin, cefazolin, chloramphenicol, flucloxacillin, gentamicin, or oxytetracyclin. The bacteria were killed or maintained at their initial density depending on the antibiotic and its concentration. The main findings were: for most drugs drop in bacterial number persisted while the concentration of the chamber remained above MIC, a period of time elapsed before recovery and bacterial multiplication resumed at the same rate as in control cultures, the period of antibacterial postantibiotic effect lasted longer with Gram-positive than with Gram-negative species, the point in time when the bacteria resumed multiplication corresponded to the IC50. We observed only minor differences in the pattern of bacteria during exposure to potentially bactericidal agents compared to antibiotics with mainly bacteriostatic effects.

Real-time interactive NMR image synthesis.

A method is presented which allows us to synthesize NMR images for arbitrary pulse sequence timing parameters in real time after user input via trackball. The synthesis is based on calculated proton density and relaxation time images obtained from a special pulse sequence. Due to the real-time operation, the method can be used both as an educational tool and for diagnostic evaluation of images assuring optimum contrast. Details of the technical implementation are given and examples are presented for spin echo as well as inversion recovery images. Finally, alternative means of presenting the density and relaxation time data are discussed which do not relate to certain pulse sequences.

Bacterial kill rates of amoxycillin and ampicillin at exponentially diminishing concentrations simulating in vivo conditions.

The responses of bacteria exposed to amoxycillin and ampicillin were studied at continuously decreasing levels with half-life values similar to those which could occur in vivo. For Escherichia coli, the kill-rates were higher with amoxycillin than with ampicillin. The bactericidal response was exponential. With an antibiotic half-life of one hour, the amoxycillin first order inactivation rate was 3.544 h-1 and the viable cell half-life was 0.196 h; the respective values for ampicillin were 2.341 h-1 and 0.296 h. With an antibiotic half-life of five hours, the inactivation rate was 0.704 h-1 corresponding to a viable cell half-life of 0.985 h for amoxycillin compared to 0.358 h-1 and 1.937 h respectively for ampicillin. Comparison of viable counts and photometric monitoring showed that the former is the preferable method for recording the bacterial response to these beta-lactam antibiotics. During the phase of exponential kill, a plateau occurred in the optical density values. This was due in part to an increased biomass per cell. During the recovery phase, the number of viable cells started to increase several hours sooner than did the rise in optical density. For Staphylococcus aureus,the rates of kill were similar with both agents. Amoxycillin had a long bacteriostatic phase which was not seen with ampicillin. This led to a longer lasting antibacterial effect and reduction to a lower total count with amoxycillin. With staphylococci, the viable counts and the photometric responses were parallel.

An in vitro model for monitoring bacterial responses to antibiotic agents under simulated in vivo conditions.

A new in vitro model for the study of bacterial responses to antibacterial agents at exponentially varying concentrations, i. e. at given elimination half-life values simulating in vivo conditions, is described. The initial concentrations and elimination rates of the agents, composition of bacterial milieu, and commencing density of the bacterial population may be altered. The principal responses of key gram-negative and gram-positive species to bactericidal and bacteriostatic agents and experimental variation are described.

[Experience with special classes for mildly brain-damaged children with behavior disorders]. / Erfahrungen mit Sonderklassen für hirnorganisch leistungsgeminderte verhaltensgestörte Kinder

Within the framework of a large-scale medical and pedagogical experiment conducted at Rostock, two special education classes for second graders were set up at the start of the 1965/66 school year in an attempt to prevent children with cerebral lesions from failing to pass courses already in the lower grades at elementary schools. As a result of this experiment, it was decided to start a school for special education children, and this school now has two parallel classes each for second, third, and fourth graders as well as one additional class in which pupils are prepared for the fifth normal education school grade. Psychological tests made as part of a longitudinal study in which 48 children who had been to this school from 1965, 1966, and 1967 were included and which spread over years including the 1971/72 school years, showed an improvement in motor development with slightly retarded intellectual development and unchanged lack of concentration power. Average attainments in the various subjects improved while pupils were attending special education classes and did not, after reintegration of such children into normal schools (fifth grade), drop below the general level of proficiency.