Biopsien von Nierenläsionen: wann und wie?

The demand for image-guided renal biopsy has increased due to the better detection of renal lesions; however, despite modern imaging techniques many small renal tumors cannot be classified as benign because they cannot be differentiated from renal cell carcinoma. Ultrasound and computed tomography (CT)-guided kidney biopsy is a safe and accurate method in the diagnostics of renal lesions and can be helpful in the selection of new ablative and pharmaceutical forms of treatment and avoid unnecessary operations. This article describes the clinical indications for an image-guided biopsy and discusses factors which should be considered when performing a biopsy.     

Murine Recombinant Angiotensin-Converting Enzyme 2: Effect on Angiotensin II-Dependent Hypertension and Distinctive Angiotensin-Converting Enzyme 2 Inhibitor Characteristics on Rodent and Human Angiotensin-Converting Enzyme 2

A newly produced murine recombinant angiotensin (Ang)-converting enzyme 2 (ACE2) was characterized in vivo and in vitro. The effects of available ACE2 inhibitors (MLN-4760 and 2 conformational variants of DX600, linear and cyclic) were also examined. When murine ACE2 was given to mice for 4 weeks, a marked increase in serum ACE2 activity was sustainable. In acute studies, mouse ACE2 (1 mg/kg) obliterated hypertension induced by Ang II infusion by rapidly decreasing plasma Ang II. These effects were blocked by MLN-4760 but not by either form of DX600. In vitro, conversion from Ang II to Ang-(1-7) by mouse ACE2 was blocked by MLN-4760 (10(-6) m) but not by either form of DX600 (10(-5) m). Quantitative analysis of multiple Ang peptides in plasma ex vivo revealed formation of Ang-(1-9) from Ang I by human but not by mouse ACE2. Both human and mouse ACE2 led to the dissipation of Ang II with formation of Ang (1-7). By contrast, mouse ACE2-driven Ang-(1-7) formation from Ang II was blocked by MLN-4760 but not by either linear or cyclic DX600. In conclusion, sustained elevations in serum ACE2 activity can be accomplished with murine ACE2 administration, thereby providing a strategy for ACE2 amplification in chronic studies using rodent models of hypertension and cardiovascular disease. Human but not mouse ACE2 degrades Ang I to form Ang-(1-9). There are also species differences regarding rodent and human ACE2 inhibition by known inhibitors such that MLN-4760 inhibits both human and mouse ACE2, whereas DX600 only blocks human ACE2 activity.     

A Randomized Trial Comparing Two Cuffed Emergency Cricothyrotomy Devices Using a Wire-Guided and a Catheter-Over-Needle Technique

Background: According to different algorithms of airway management, emergency cricothyrotomy is the final step in managing the otherwise inaccessible airway. As an alternative to an open surgical procedure, minimally invasive approaches exist. Various sets for different methods are commercially available. QuickTrach™ (VBM Medizintechnik GmbH, Sulz am Neckar, Germany) contains a plastic cannula over a metal needle for direct placement in the trachea, whereas a guide-wire is used for the actual placement of the cannula in the Melker Set™ (Cook Group Incorporated, Bloomington, IN). Objective: We hypothesize that the direct puncture involving less discrete steps is faster to perform. However, it will lead to more complications due to the higher force needed to place the relatively thick needle. Method: After approval of the local ethics committee, the study was performed on cadavers of 16 adult sheep. A wire-guided cricothyrotomy was compared with a catheter-over-needle technique. Successful placement and performance time were compared. Complication rate and maximal achieved airway pressure were evaluated. Data is given as mean and interquartile range, and Mann-Whitney U-test (p < 0.05) for significant differences. Results: With the wire-guided technique, successful placement was possible in all attempts. The catheter-over-needle method was successful in 63% and had a higher complication rate (75% vs. 13%). The cannula-over-needle method allowed a faster cricothyrotomy (32 [2–34] vs. 53 [52–56] s). Both methods allowed the delivery of similar maximal airway pressures (50 [44–51] vs. 48 [43–53] mbar). Conclusion: The wire-guided method proved to be the more reliable technique, leading to fewer complications. However, the direct puncture was faster to perform. Placed accurately, both devices allowed sufficient ventilation.     

Mood-dependent learning. II. Healthy subjects--influence of positive and negative feedback on expectancy shifts

Changes of success expectancy in healthy test persons are investigated in this study. An experimental mood manipulation with the help of mood statements by Velten [1968] was performed. Changes of success expectancy were rather attributable to the present mood than to the trait-component 'depression'.     

Inter-study reproducibility of cardiovascular magnetic resonance myocardial feature tracking

Background

Cardiovascular magnetic resonance myocardial feature tracking (CMR-FT) is a recently described method of post processing routine cine acquisitions which aims to provide quantitative measurements of circumferentially and radially directed ventricular wall strain. Inter-study reproducibility is important for serial assessments however has not been defined for CMR-FT.

Methods

16 healthy volunteers were imaged 3 times within a single day. The first examination was performed at 0900 after fasting and was immediately followed by the second. The third, non-fasting scan, was performed at 1400.CMR-FT measures of segmental and global strain parameters were calculated. Left ventricular (LV) circumferential and radial strain were determined in the short axis orientation (Ecc_SAX and Err_SAX respectively). LV and right ventricular longitudinal strain and LV radial strain were determined from the 4-chamber orientation (Ell_LV, Ell_RV, and Err_LAX respectively). LV volumes and function were also analysed.Inter-study reproducibility and study sample sizes required to demonstrate 5% changes in absolute strain were determined by comparison of the first and second exams. The third exam was used to determine whether diurnal variation affected reproducibility.

Results

CMR-FT strain analysis inter-study reproducibility was variable. Global strain assessment was more reproducible than segmental analysis. Overall Ecc_SAX was the most reproducible measure of strain: coefficient of variation (CV) 38% and 20.3% and intraclass correlation coefficient (ICC) 0.68 (0.55-0.78) and 0.7 (0.32-0.89) for segmental and global analysis respectively. The least reproducible segmental measure was Ell_RV: CV 60% and ICC 0.56 (0.41-0.69) whilst the least reproducible global measure was Err_LAX: CV 33.3% and ICC 0.44 (0–0.77). Variable reproducibility was also reflected in the calculated sample sizes, which ranged from 11 (global Ecc_SAX) to 156 subjects (segmental Ell_RV). The reproducibility of LV volumes and function was excellent. There was no diurnal variation in global strain or LV volumetric measurements.

Conclusions

Inter-study reproducibility of CMR-FT varied between different parameters, as summarized above and was better for global rather than segmental analysis. It was not measurably affected by diurnal variation. CMR-FT may have potential for quantitative wall motion analysis with applications in patient management and clinical trials. However, inter-study reproducibility was relatively poor for segmental and long axis analyses of strain, which have yet to be validated, and may benefit from further development.     

Influence of age on outcome of mechanically ventilated patients in an intensive care unit.

OBJECTIVE: To assess the influence of age on the outcome of patients receiving prolonged mechanical ventilation. DESIGN: Retrospective study. SETTING: Intensive care unit. PATIENTS: A total of 1,141 patients in our ICU during a 32-month period. A total of 536 patients required mechanical ventilation. After exclusion of 171 patients ventilated for less than 24 hrs after surgery, 365 patients were investigated. MEASUREMENTS AND MAIN RESULTS: Two hundred sixty-six (73%) patients were aged less than 70 yrs; 99 (27%) patients were greater than or equal to 70 yrs. There was no significant difference in mortality rate between the younger and the older age groups. There was no significant influence of other important factors, such as severity of illness, duration of mechanical ventilation, or length of ICU stay. The only factor showing a significant influence on patient outcome was the reason for mechanical ventilation. There were more survivors in the group being ventilated because of ventilatory insufficiency than in the group with oxygenation impairment (57.8% vs. 23.9%, p less than .001). CONCLUSION: An influence of age on the outcome of mechanically ventilated patients in the ICU could not be ascertained in this study.     

Complete genome sequence and analysis of Wolinella succinogenes

To understand the origin and emergence of pathogenic bacteria, knowledge of the genetic inventory from their nonpathogenic relatives is a prerequisite. Therefore, the 2.11-megabase genome sequence of Wolinella succinogenes, which is closely related to the pathogenic bacteria Helicobacter pylori and Campylobacter jejuni, was determined. Despite being considered nonpathogenic to its bovine host, W. succinogenes holds an extensive repertoire of genes homologous to known bacterial virulence factors. Many of these genes have been acquired by lateral gene transfer, because part of the virulence plasmid pVir and an N-linked glycosylation gene cluster were found to be syntenic between C. jejuni and genomic islands of W. succinogenes. In contrast to other host-adapted bacteria, W. succinogenes does harbor the highest density of bacterial sensor kinases found in any bacterial genome to date, together with an elaborate signaling circuitry of the GGDEF family of proteins. Because the analysis of the W. succinogenes genome also revealed genes related to soil- and plant-associated bacteria such as the nif genes, W. succinogenes may represent a member of the epsilon proteobacteria with a life cycle outside its host.     

Peroxisome proliferator-activated receptor gamma gene locus is related to body mass index and lipid values in healthy nonobese subjects

The peroxisome proliferator-activated receptor gamma (PPARgamma) gene has been implicated in morbid obesity and is important to lipid and carbohydrate metabolism. However, the relevance of gene variations in healthy nonobese subjects has not been defined. We recruited monozygotic and dizygotic healthy nonobese twin subjects to test the hypothesis that the PPARgamma gene is important to body mass index and lipid concentrations in healthy nonobese subjects. Both linkage and association strategies were used in the same dizygotic twins. The PPARgamma gene locus was linked (P<0.01) to high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and body mass index as quantitative traits. A biallelic variant in the PPARgamma gene was associated with high-density lipoprotein cholesterol and body mass index (P<0.05). We also looked for linkage between the same variables and the retinoic X receptor gene locus. This locus was linked to total and low-density lipoprotein cholesterol as well as triglycerides. We conclude that the PPARgamma gene is highly relevant to lipid metabolism and body mass index, not only in the morbidly obese but also in healthy nonobese subjects. The same appears to be true for its binding partner. Sequencing these genes in twins would serve to identify gene variations contributing to body mass index and lipid concentrations in healthy nonobese subjects.     

Analysis of the B cell repertoire against autoantigens in patients with giant cell arteritis and polymyalgia rheumatica

The analysis of the antibody repertoire of patients with giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) might identify target antigens of the autoimmune response with potential relevance to our understanding of the pathogenesis of the disease and to the development of serodiagnostic tests. To detect such antigens, we screened a cDNA library derived from normal human testis for antigens reacting with IgG antibodies in the 1 : 250 diluted sera of three patients with untreated GCA using SEREX, the serological identification of antigens by recombinant cDNA expression cloning. Of 100 000 clones screened with each serum, six, 28 and six clones, respectively, were positive, representing a total of 33 different antigens. Most of the antigens reacted only with the serum used for identification and/or at a similar frequency with normal control sera. However, lamin C and the nuclear antigen of 14 kD reacted specifically with 32% of GCA/PMR, but with none of the control sera, while human cytokeratin 15, mitochondrial cytochrome oxidase subunit II, and a new gene product were detected preferentially, but not exclusively by sera from GCA/PMR patients. We conclude that patients with GCA/PMR develop antibodies against a broad spectrum of human autoantigens. Antibodies against human lamin C, the nuclear autoantigen of 14 kD as well as human cytokeratin 15, mitochondrial cytochrome oxidase subunit II and the product of a new gene should be investigated further to determine their value as tools for the diagnosis and/or the definition of clinical subgroups of patients with GCA/PMR.