Preliminary Research on Relationship Between Dielectric Property and Microstructure of Rabbit Liver

The dielectric properties in vitro present characteristic changes along with the alteration of metabolic activities, which can be detected from tissue micro- structure. The dielectric properties of tissues are closely related to its viability, but the relationship remains unclear to us. This study aims to specify the relationship between dielectric parameters and microstructure of living tissues and to try to explain the influence of tissue viability on dielectric properties. Nine rabbits were studied in this experiment. The impedance spectroscopy （10 Hz-1 MHz） and microstructure were determined at different time intervals （from 5 rain to 7 h） after samples were prepared. Some characteristic parameters were extracted to analyze the relationship between them. The inactivation process characterized by the mierostrueturs could be detected by means of dielectric parameters： the microstructures had no obvious change within 30 rain a.nd cell swelling caused by osmosis led to the decrease of extracellular ion concentration, resulting in the rise of lowfrequency impedance after 30 rain. The reduction of impedance was accompanied by the expanding intercellular area and irregular cell shape caused by the gradual destruction of cell membrane.The functions between alteration rate of intercellular area and Cole-Cole model parameters were also established. There is a strong correlative relationship between dielectric properties and microstructure. The dielectric spectrum can be a rapid and innocuous method to monitor the status of tissues. In the future, it may be of great help for clinical application, especially in transplantation.     

Neue Behandlungskonzepte in der pädiatrischen Notfallversorgung

Technological innovations and the advent of standardized training formats, including high technology simulation laboratories have recently improved and facilitated pediatric emergency management. The proof of concept, actual impact and effectiveness of these changes have been evaluated in animal models, analysis of case series and skill improvement testing after training. In one of the most significant advances, efficient intraosseous vascular access can be established in less than 1 min using an electrical hand-held drill. Pediatric respiratory insufficiency can usually be managed with respiratory support via a face mask and bag; however, in patients with a difficult airway, laryngeal masks are an extremely useful device for airway management which can be trained with relative ease. Intubation is suitable only for physicians with relevant expertise. Additional escalation strategies for respiratory support include non-invasive ventilation prior to intubation. The current guidelines of the European Resuscitation Council recommend a chest compression-ventilation ratio of 15:2 which will result in improved coronary perfusion and higher training efficiency. Pharmacological resuscitation with adrenalin should only be performed using standard dosage via intravenous or intraosseous access. Hypothermia for neuroprotection after successful resuscitation of children has been shown to be effective for term newborn infants but currently no general recommendations for the pediatric population are possible. In the absence of an intravenous access, nasal administration of drugs results in rapid resorption and can be used for anticonvulsive treatment or even for analgesia/sedation. Crucial for successful treatment of pediatric septic shock is early and aggressive intravenous fluid resuscitation (up to 60 ml/kg) using chrystalloid solutions, so-called early goal directed therapy. Point-of-care ultrasound meanwhile significantly contributes to improved results for in-hospital pedriatric emergency management. In this paper, recommendations of pediatric and emergency societies are provided, the current literature is discussed and personal experience is reported in selected topics.     

Tumor Necrosis Factor‐α and Oral Inflammation in Patients With Crohn Disease

Background: Crohn disease (CD) is a chronic inflammatory bowel disease often accompanied by periodontal symptoms. Based on its function in immune response, tumor necrosis factor (TNF)‐α and its genetic variants have been discussed as risk indicators in inflammatory processes. Therefore, the aim of the present study is to investigate the impact of TNF‐α polymorphisms on periodontal parameters and inflammatory lesions of oral mucosa as a characteristic of CD. Methods: A total of 142 patients with CD were included in the study. Oral soft tissue alterations and periodontal parameters were assessed. Genotypes, alleles, and haplotypes of TNF‐α polymorphisms (rs1800629, cDNA?308G > A; and rs361525, cDNA?238G > A) were determined by polymerase chain reaction with sequence‐specific primers (PCR‐SSP). Results: Patients with CD who exhibit more severe oral soft tissue alterations were significantly more often A allele carriers of rs361525 than G allele carriers (14.2% versus 2.2%; P <0.001). Furthermore, A allele carriers had a higher mean periodontal probing depth (P <0.05), mean clinical attachment level (P <0.05), and sites with bleeding on probing (not significant). Similar results were obtained when evaluating A allele‐containing genotypes (AG + AA) and haplotypes (GA). In multivariate analyses considering age, sex, smoking, and medication as confounders, the A allele was proven to be an independent risk indicator for oral soft tissue alterations in patients with CD. No genotype‐dependent influence of rs1800629 was observed. Conclusion: The TNF‐α A allele of rs361525 represents a significant risk indicator for oral soft tissue alterations in patients with CD.     

Deficient expression of the small proteoglycan decorin in a case of severe/lethal osteogenesis imperfecta

In osteogenesis imperfecta (OI) the effects of mutations in type I collagen genes generally reflect their nature and localization. Unrelated individuals sharing identical mutations present, in general, similar clinical phenotypes. However, in some such cases the clinical phenotype differs. This variable clinical expression could be the result of abnormalities in other connective tissue proteins. Since decorin is a component of connective tissue, binds to type I collagen fibrils and plays a role in matrix assembly, we studied decorin production in skin fibroblasts from OI patients. Cultured fibroblasts from one patient with extremely severe osteogenesis imperfecta (classified as type II/III) who has an α1(I)gly415ser mutation were found to secrete barely detectable amounts of decorin into culture medium. Western blotting using antibodies raised against decorin confirmed the reduction of the decorin core protein and Northern blot analysis showed decorin mRNA levels below the limit of detection. Cells from a patient, with a less severe phenotype, bearing a mutation in the same position of the triple helix (α1(I)gly415) expressed decorin normally. The different clinical phenotypes could be due to the differing genetic backgrounds of the patients so it is tempting to conclude that in our most severely affected patient the absence of decorin aggravates the clinical phenotype. © 1996 Wiley-Liss, Inc.     

Qualitative and quantitative analysis of glycine- and GABA-immunoreactive nerve terminals on motoneuron cell bodies in the cat spinal cord: A postembedding electron microscopic study

The distribution of glycine- and gamma-aminobutyric acid (GABA)-like immunoreactivity (LI) in nerve terminals on the cell soma of motoneurons in the aldehyde-fixed cat L7 spinal cord was examined using postembedding immunogold histochemistry in serial ultrathin sections. Quantitative examination of 405 terminals on eight neurons of α-motoneuron size in the L7 motor nuclei from one animal was performed. A majority of the terminals (69%) were immunoreactive to glycine and/or GABA. These terminals contained flat or oval synaptic vesicles, thus classifying them as F type or as C type in one case. In no case was a type-F terminal unlabeled for both glycine and GABA. Most of the immunolabeled terminals were immunoreactive to glycine only (62.5%), whereas 35.4% contained both glycine- and GABA-LI. A very small number of immunolabeled terminals (2%) were immunoreactive to GABA only. In those terminals, where glycine- and GABA-LI coexisted, the gold particle density for each amino acid was only half of that seen in boutons containing only one of the two amino acids. The involvement of glycine and GABA in postsynaptic inhibition of spinal α-motoneurons is discussed, with particular reference to the possibility that these two inhibitory amino acids may be coreleased from a significant proportion of the nerve terminals impinging on the cell bodies. © 1996 Wiley-Liss, Inc.     

Stage-related differences of mitotic and apoptotic indices,and bcl-2 protein expression in diffusely growing non-Hodgkin's lymphomas

The present study examined whether growth characteristics of diffusely growing non-Hodgkin's lymphomas (NHL) may differ as a function of stage. Among 105 NHL of various types and sub-types (REAL [Revised European-American Lymphoma] classification), localized (Ann Arbor pathologic stages I + II) lymphomas exhibited clearly higher indices for mitotic activity, apoptosis and cell turnover, as well as a significantly lower percentage of cells containing immunohistochemically detectable bcl-2 protein, than disseminated (stages III + IV) NHL. A similar pattern emerged when high-grade (Kiel classification) lymphomas only were evaluated. Low-grade NHL showed analogous, but less marked, stage-dependent characteristics, with the exception of median percentages of bcl-2⁺ cells, which remained comparable in all stages. Our findings are consistent with the notion that dissemination of diffusely growing NHL is usually associated with reduced cell turnover and, in high-grade lymphomas, with the generation of longer-lived cells. © 1996 Wiley-Liss, Inc.