Gentamicin susceptibility in Escherichia coli related to the genetic background: problems with breakpoints

In total, 120 Escherichia coli isolates positive for one of the gentamicin resistance (GEN(R)) genes aac(3)-II, aac(3)-IV or ant(2')-I were tested for gentamicin susceptibility by the agar dilution method. Isolates positive for aac(3)-IV or ant(2')-I had an MIC distribution of 8-64 mg/L, whereas isolates positive for aac(3)-II had MICs of 32 to >512 mg/L, suggesting a relationship between the distribution of MICs and the specific GEN(R) mechanism. The MIC distribution, regardless of the GEN(R) mechanism, was 8 - >512 mg/L, which supports the clinical breakpoint of MIC >4 mg/L suggested by EUCAST and questions the breakpoint recommended by the CLSI (> or =16 mg/L).     

Lamina propria plasma cells in inflammatory bowel disease: intracellular detection of immunoglobulins using flow cytometry

This is the first application of flow cytometry for the detection of lamina propria plasma cells and their intracellular immunoglobulins in patients with inflammatory bowel disease compared to healthy controls. The study has been focused on the distribution of IgA, IgG, IgM and the four IgG subclasses. Plasma cells were detected as high CD38 positive cells. For fixation and permeabilisation a single step reagent, Ortho Permeafix®, was used.

By flow cytometry, in patients with inflammatory bowel disease compared to healthy controls, a higher percentage of IgG⁺ cells can be observed, in Crohn's disease also a higher percentage of IgM⁺ cells. Regarding the IgG subclass distribution, patients with Crohn's disease show an increase in IgG2⁺ cells, patients with ulcerative colitis an increase in IgG1⁺ and IgG3⁺ cells. These results do agree with and expand the results of earlier immunohistochemical and functional studies, which are favoured today. For the determination of lymphocyte subset proportions and the detection of intracellular antigens, flow cytometry provides a useful alternative to well-established immunohistochemical methods. By analysing a larger number of cells, this method is more reproducible and less prone to interobserver variations than immunohistochemistry, which needs the pre-selection of a mucosal area, the microscopic scoring of a limited number of cells and the circumvention of high background staining. The optimized flow cytometric protocol used in this study might be a promising tool for further investigations of various purposes.     

Involvement of the immune system in the pathogenesis of Crohn's disease. Expression of the T9 antigen on peripheral immunocytes correlates with the severity of the disease

Peripheral lymphocyte cells from patients suffering from Crohn's disease were analyzed for the expression of the "activation" antigens T9 and HLA-DR on their cell surface. It was found that high numbers of "activated" lymphocytes, the majority of which have proven to be T cells, could be detected in patients with active Crohn's disease, whereas in healthy controls and inactive disease only a small subfraction of lymphocytes was positive for these antigens. This difference was highly significant (p = 0.0001). Within the subpopulation of T9-positive cells the ratio between T4- and T8-positive cells is about 1.8 (compared with 2.0 in the total T-cell subset). All HLA-DR-positive, non-B and non-glass-adherent cells could be detected in the T9-positive cell fraction. The presence of T9 antigens was found to correlate with the grade of severity of the disease as assessed by a Crohn's disease activity index. The presence of high amounts of T cells exhibiting this antigen is not restricted to Crohn's disease but is thought to be of importance as a marker for the involvement of the immune system in other maladies as well. Nevertheless, the determination of T9 antigen is expected to provide objective data reflecting the severity of Crohn's disease.     

Absolute concentrations of high-energy phosphate metabolites in normal,hypertrophied, and failing human myocardium measured noninvasively with (31)P-SLOOP magnetic resonance spectroscopy

OBJECTIVE: The purpose of the present study was to measure absolute concentrations of phosphocreatine (PCr) and adenosine triphosphate (ATP) in normal, hypertrophied, and failing human heart. BACKGROUND: Conflicting evidence exists on the extent of changes of high-energy phosphate metabolites in hypertrophied and failing human heart. Previous reports using phosphorus-31 magnetic resonance spectroscopy ((31)P-MRS) have quantified metabolites in relative terms only. However, this analysis cannot detect simultaneous reductions. METHODS: Four groups of subjects (n = 10 each), were studied: volunteers and patients with hypertensive heart disease (HHD), aortic stenosis, and dilated cardiomyopathy (DCM). Left ventricular (LV) function and mass were measured by cine magnetic resonance imaging. Absolute and relative concentrations of PCr and ATP were determined by (31)P-MRS with spatial localization with optimum point spread function. RESULTS: Left ventricular ejection fraction remained normal in HHD and aortic stenosis, but was severely reduced to 18% in DCM; LV mass was increased by 55%, 79%, and 68% respectively. In volunteers, PCr and ATP concentrations were 8.82 +/- 1.30 mmol/kg wet weight and 5.69 +/- 1.02 mmol/kg wet weight, and the PCr/ATP ratio was 1.59 +/- 0.33. High-energy phosphate levels were unaltered in HHD. In aortic stenosis, PCr was decreased by 28%, whereas ATP remained constant. In DCM, PCr was reduced by 51%, ATP by 35%, and reduction of the PCr/ATP ratio by 25% was of borderline significance (p = 0.06). Significant correlations were observed among energetic and functional variables, with the closest relations for PCr. CONCLUSIONS: In human heart failure due to DCM, both PCr and ATP are significantly reduced. Ratios of PCr to ATP underestimate changes of high-energy phosphate levels.     

Transseptal use of high-density grid catheter for VT mapping and retrograde hemodynamic support with Impella pump in presence of Mitraclips

Journal of Interventional Cardiac Electrophysiology - We sought to establish the technical feasibility of VT-mapping with high-density catheters in patients with Mitraclips, requiring a hemodynamic...     

Determination of secretory immunoglobulin A in the saliva of children with recurrent and chronic respiratory tract diseases during a stay at a health resort

Investigations of sIgA-concentrations in saliva of 101 children in age of 2 to 4 years with recurrent and chronic airways diseases were performed by means of a sIgA specific enzyme linked immunoassay. The aim was to find out immunodeficiencies in comparison to healthy children (n = 50), and to test whether or not there is an influence of medical and climate treatment over a period of 8 weeks onto sIgA values in saliva. Only 3 children showed decreased sIgA concentrations. There were no differences between patients and healthy children because of the great interindividual variances of sIgA concentrations. An effect of climate cure to sIgA values could not be shown.