The Potential of Anti-Bullying Efforts to Prevent Academic Failure and Youth Crime. A Case Using the Olweus Bullying Prevention Program (OBPP)

Prevention Science - The effectiveness of bullying prevention programs has led to expectations that these programs could have effects beyond their primary goals. By reducing the number of victims...     

Distinct immunopathological mechanisms of EBV-positive and EBV-negative posttransplant lymphoproliferative disorders

EBV-positive and EBV-negative posttransplant lymphoproliferative disorders (PTLDs) arise in different immunovirological contexts and might have distinct pathophysiologies. To examine this hypothesis, we conducted a multicentric prospective study with 56 EBV-positive and 39 EBV-negative PTLD patients of the K-VIROGREF cohort, recruited at PTLD diagnosis and before treatment (2013–2019), and compared them to PTLD-free Transplant Controls (TC, n = 21). We measured absolute lymphocyte counts (n = 108), analyzed NK- and T cell phenotypes (n = 49 and 94), and performed EBV-specific functional assays (n = 16 and 42) by multiparameter flow cytometry and ELISpot-IFNγ assays (n = 50). EBV-negative PTLD patients, NK cells overexpressed Tim-3; the 2-year progression-free survival (PFS) was poorer in patients with a CD4 lymphopenia (CD4⁺<300 cells/mm³, p <  .001). EBV-positive PTLD patients presented a profound NK-cell lymphopenia (median = 60 cells/mm³) and a high proportion of NK cells expressing PD-1 (vs. TC, p = .029) and apoptosis markers (vs. TC, p < .001). EBV-specific T cells of EBV-positive PTLD patients circulated in low proportions, showed immune exhaustion (p = .013 vs. TC) and poorly recognized the N-terminal portion of EBNA-3A viral protein. Altogether, this broad comparison of EBV-positive and EBV-negative PTLDs highlight distinct patterns of immunopathological mechanisms between these two diseases and provide new clues for immunotherapeutic strategies and PTLD prognosis.     

Untersuchungen über die Ausspritzmethode zur Lokalisation der Mikroelektrodenspitze bei Potentialmessungen am proximalen Konvolut der Rattenniere

Summary In measurements of transtubular potential differences of the rat kidney, reported previously, the electrode tip could be localized by ejection of electrode fluid under microscopic observation. In the proximal tubule it was found in contrast to the distal tubule that all potential differences disappeared irreversibly upon fluid ejection. The present study is concerned with the mechanism underlying this effect.The localization of the puncturing electrode was controlled by a coupling pulse technique. Current pulses were injected into the tubular lumen through a first electrode, and the same tubule was punctured subsequently with a second electrode which measured the potential difference. It was found that in most impalements the puncturing electrode would stop within the tubular wall, although from microscopic inspection it appeared to have reached the tubular lumen. Furthermore, when fluid was ejected from the electrode tip, the electrode abruptly penetrated into the tubular lumen. Simultaneously the potential difference recorded hitherto disappeared. This coincidence suggests that the breakdown of the potential difference merely corresponds to the potential step between cellular compartment and tubular lumen and that it is not caused by a transtubular leak.Conclusive evidence against the development of leaks during fluid ejection was derived from microperfusion experiments. During perfusion of the tubular lumen with choline chloride solution proximal tubules develop a transtubular potential difference significantly different from zero (up to 30 mV, lumen positive). Whether the electrode entered the tubular lumen during the impalement immediately, or whether the penetration was only accomplished by fluid ejection, did not affect the magnitude of the positive potential differences recorded. Hence these experiments constitute proof that the method of fluid ejection permits reliable measurements of transtubular potential differences in the proximal tubule. They confirm our finding that under normal free flow conditions no transtubular potential difference exists across the proximal tubular epithelium of the rat kidney.

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Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Nocardia ignorata, a new agent of human nocardiosis isolated from respiratory specimens in Europe and soil samples from Kuwait

Nocardia ignorata is a recently described species identified on the basis of a single isolate of unknown origin. Here we describe the epidemiological, phenotypic, and phylogenetic characteristics of this new species, based on five new clinical and soil isolates.     

Acoustic voice analysis by means of the hoarseness diagram.

The hoarseness diagram (Michaelis, Fr?hlich, & Strube, 1998a) has been proposed as a new approach to describe different acoustic properties of voices. To test its performance in the analysis of pathologically disturbed and normal voices five requirements are suggested that should be met by any acoustic voice-analysis protocol to be used in voice research and clinical practice. The hoarseness diagram is then tested with regard to these requirements. Individual voices are found to show a satisfactory localization in the diagram. Aspects of stationarity are discussed in the context of four case studies. The different cases illustrate that changes in the acoustic analysis results are observed if the voice-generation conditions change, whereas results are stationary if phonation conditions do not change. Different pathological voice groups defined on grounds of the specific phonation mechanism are found to map to specific regions of the hoarseness diagram, with differences between group locations being significant. All results can be interpreted without exceptions if the two hoarseness diagram coordinates are taken to reflect the vibrational irregularity of the voice-generation mechanisms on the one side and the degree of closure of the vibrating structures on the other side. The hoarseness diagram and its underlying algorithms are thus shown to constitute a useful approach to acoustic voice analysis in research and clinical practice. The tests themselves demonstrate several application possibilities, including the quantitative monitoring of individual voices.     

Costs of the treatment of leg ulcers: initiating a quality assurance process

Reports on a study which aimed to initiate a quality assurance process among health care personnel in Sweden. An epidemiological survey concerning treatment of leg ulcers in a defined region in Sweden was conducted and the costs of treating leg ulcers at different levels of care were analysed. The epidemiological survey provided the data necessary to calculate the socio-economic costs for the treatment of leg ulcers. The weekly cost was found to be about 24 times higher for hospital inpatients than it was for patients treated at home. The quality assurance process has continued through an interdisciplinary regional consensus conference and the establishment of a consensus programme in the region, with targets and general suggestions for the care and treatment of leg ulcers. To maintain high quality in leg ulcer treatment in the region, an interdisciplinary reference group has been established with members from different clinics at the hospital and members from the primary health care.     

No association between secretor status of ABO blood group antigens and juvenile periodontitis

The aim of this study was to determine the association between secretor status of ABO blood group antigens and localized juvenile periodontitis (LJP). Forty-three patients with LJP (mean age 20.8 years) diagnosed according to Baer's criteria were selected. Thirty two periodontally healthy normal subjects (mean age 24.7 years) were use as control. Samples of blood and saliva were collected from patients and from control subjects. ABO blood group was determined by agglutination of erythrocytes with appropriate antisera. Determination of soluble ABO antigens in saliva was made by the haemagglutination inhibition assay. Subjects with O blood group were most frequent in both groups. The distribution of blood groups, and secretor and non-secretor status of ABO group antigens in LJP patients and control subjects was not significant. The results provide support for the hypothesis that there is no association between non-secretor status and LJP.     

Analysing ion channels with hidden Markov models

Ion channel current amplitudes () and open probabilities (P _o) have been analysed so far by defining a 50% threshold to distinguish between open and closed states of the channels. With this standard method (SM) it is very difficult or even impossible to analyse channels of different size in one membrane patch correctly. A stochastical model, named the hidden Markov model (HMM), separates between observation noise and the stochastic process of opening and closing of ion channels. The HMM allows the independent analysis of , P _o, and mean dwell times () of different channels in one membrane patch, without defining threshold levels. Using this method errors in the analysis are not summarized like in the SM because all different analysing procedures (e. g. filtering, setting of threshold, fitting processes) are done in one step. Two different K⁺ channels in excised basolateral membranes of the cortical collecting duct of rat (CCD) were analysed by the SM and the HMM. The value of the intermediate-conductance K⁺ channel (i-K⁺) was 3.9±0.1 pA (SM) and 3.8±0.2 pA (HMM) for 11 observations. The P _o value of this channel was 10.2±4.2% (SM) and 10.1±4.0% (HMM). The mean values were 5.4±0.6 ms for the open state and 9.6±2.2 ms and 145±21 ms for the closed states (SM) and 7.8±1.1 ms, 7.7±0.9 ms and 148±24 ms (HMM), respectively. For seven small-conductance K⁺ (s-K⁺) channels, which were found in the same membrane patches as the i-K⁺, an accurate analysis of P _o and was not possible with the SM. The value was 1.0±0.1 (SM), 0.9±0.1 (HMM) pA. P _o was 16.6±4.6%, the open value was 11.1±2.8 ms, and the closed value was 34.9±8.5 ms. The HMM allows the analysis of single-channel currents, P _o, and mean values when different or more than one ion channel(s) are colocalized in one membrane patch. Where analysis with the SM was possible results did not significantly differ from those obtained with the HMM. Thus for this kind of analysis the method of setting a 50% threshold appears justified.     

Use of polymerase chain reaction in human African trypanosomiasis stage determination and follow-up.

Stage determination of human African trypanosomiasis is based on the detection of parasites and measurements of biological changes in the cerebrospinal fluid (CSF) (concentration of white blood cells > 5 cells per mm3 and increased total protein levels). The patient is treated accordingly. Demonstration of the absence or presence of trypanosomes by the double centrifugation technique is still the only test available to clinicians for assessing treatment success. In this study, however, we evaluate the polymerase chain reaction (PCR) as a tool for assessing the disease stage of trypanosomiasis and for determining whether treatment has been successful. All 15 study patients considered to be in the advanced stage of the disease were PCR positive; however, trypanosomes were demonstrated by double centrifugation in only 11 patients. Of the five remaining patients, who were considered to be in the early stage, PCR and double centrifugation were negative. Following treatment, 13 of the 15 second-stage patients were found to be negative for the disease in at least two samples by PCR and double centrifugation. Two others were still positive by PCR immediately and one month after the treatment. Trypanosome DNA detection using PCR suggested that the two positive patients were not cured but that their possible relapse could not be identified by a search for parasites using the double centrifugation technique. Further evaluation of the PCR method is required, in particular to determine whether PCR assays could be used in studies on patients who fail to respond to melarsoprol, as observed in several foci.