Surface pretreatments for medical application of adhesion

Medical implants and prostheses (artificial hips, tendono- and ligament plasties) usually are multi-component systems that may be machined from one of three material classes: metals, plastics and ceramics. Typically, the body-sided bonding element is bone.     

Strain and strain rate parametric imaging. A new method for post processing to 3-/4-dimensional images from three standard apical planes. Preliminary data on feasibility, artefact and regional dyssynergy visualisation

Background

We describe a method for 3-/4D reconstruction of tissue Doppler data from three standard apical planes, post processing to derived data of strain rate/strain and parametric colour imaging of the data. The data can be displayed as M-mode arrays from all six walls, Bull's eye projection and a 3D surface figure that can be scrolled and rotated. Numerical data and waveforms can be re-extracted.

Methods

Feasibility was tested by Strain Rate Imaging in 6 normal subjects and 6 patients with acute myocardial infarction. Reverberation artefacts and dyssynergy was identified by colour images. End systolic strain, peak systolic and mid systolic strain rate were measured.

Results

Infarcts were visualised in all patients by colour imaging of mid systolic strain rate, end systolic strain and post systolic shortening by strain rate. Reverberation artefacts were visible in 3 of 6 normals, and 2 of 6 patients, and were identified both on bull's eye and M-mode display, but influenced quantitative measurement. Peak systolic strain rate was in controls minimum -1.11, maximum -0.89 and in patients minimum -1.66, maximum 0.02 (p = 0.04). Mid systolic strain rate and end systolic strain did not separate the groups significantly.

Conclusion

3-/4D reconstruction and colour display is feasible, allowing quick visual identification of infarcts and artefacts, as well as extension of area of post systolic shortening. Strain rate is better suited to colour parametric display than strain.     

Hormone replacement therapy in rheumatoid arthritis is associated with lower serum levels of soluble IL-6 receptor and higher insulin-like growth factor 1

Hormone replacement therapy (HRT) modulates the imbalance in bone remodeling, thereby decreasing bone loss. Sex hormones are known to influence rheumatic diseases. The aim of this study was to investigate the effects of HRT on the serum levels of hormones and cytokines regulating bone turnover in 88 postmenopausal women with active rheumatoid arthritis (RA) randomly allocated to receive HRT plus calcium and vitamin D3 or calcium and vitamin D3 alone for 2 years. An increase in estradiol (E2) correlated strongly with improvement of bone mineral density in the hip (P < 0.001) and lumbar spine (P < 0.001). Both baseline levels and changes during the study of IL-6 and erythrocyte sedimentation rate were correlated positively (P < 0.001). HRT for 2 years resulted in an increase of the bone anabolic factor, insulin-like growth factor 1 (IGF-1) (P < 0.05) and a decrease of serum levels of soluble IL-6 receptor (sIL-6R) (P < 0.05), which is known to enhance the biological activity of IL-6, an osteoclast-stimulating and proinflammatory cytokine. Baseline levels of IL-6 and IGF-1 were inversely associated (P < 0.05), and elevation of IGF-1 was connected with decrease in erythrocyte sedimentation rate (P < 0.05) after 2 years. Interestingly, increase in serum levels of E2 was associated with reduction of sIL-6R (P < 0.05) and reduction of sIL-6R was correlated with improved bone mineral density in the lumbar spine (P < 0.05). The latter association was however not significant after adjusting for the effect of E2 (P = 0.075). The influences of IGF-1 and the IL-6/sIL-6R pathways suggest possible mechanisms whereby HRT may exert beneficial effects in RA. However, to confirm this hypothesis future and larger studies are needed.     

Desmoid tumors of the abdominal wall: A case report

Background  

Desmoid tumors are slow growing deep fibromatoses with aggressive infiltration of adjacent tissue but without any metastatic potential.     

Metabolic phenotype of phosphoglucose isomerase mutants of Corynebacterium glutamicum

A series of experiments reported in the literature using fluxomics as an efficient functional genomics tool revealed that the L-lysine production of the Corynebacterium glutamicum strain MH20-22B correlates with the extent of intracellular NADPH supply. Some alternative metabolic engineering strategies to increase intracellular NADPH supply in the C. glutamicum strain DSM5715 were considered and finally the redirection of carbon flux through the pentose phosphate pathway with two NADPH generating enzymatic reactions was favored. Elsewhere, the construction of a phosphoglucose isomerase (Pgi) null mutant of the C. glutamicum strain DSM5715 has been described by utilizing genetic engineering as well as some aspects of its metabolic phenotype. Most interestingly, it was shown that not only could the L-lysine formation be increased by 1.7-fold but the by-product concentration for the null mutant strain was also able to be drastically reduced. In this publication we discuss this metabolic phenotype in detail and present additional data on by-product formation as well as yield considerations. Results from isotope based metabolic flux analysis in combination with considerations on NADPH metabolism clearly exclude the existence of Pgi isoenzymes in C. glutamicum strain DSM5715. The genome region containing the pgi gene was analyzed. It cannot be excluded that polar effects might have been caused by the disruption of the pgi gene and might have contributed to the observed metabolic phenotype of C. glutamicum Pgi mutants. We illustrate growth characteristics of a Pgi mutant of an industrial L-lysine production strain. A reduced growth rate and a biphasic growth behavior was observed. The importance of NADPH reoxidation for well balanced growth in Pgi mutants is discussed. Another phosphoglucose isomerase mutant of C. glutamicum has been described in literature with which an increase in L-lysine yield from 42 to 52% was observed. This finding highlights the general potential of metabolic flux redirection towards the pentose phosphate pathway, which could be used for metabolic engineering of the biotechnological synthesis of (1) aromatic amino acids and (2) chemicals whose synthesis depends on intracellular NADPH supply.     

Nuclear staining for the small heat shock protein alphaB-crystallin colocalizes with splicing factor SC35

AlphaB-Crystallin has for a long time been considered a specific eye lens protein. Later on it appeared that this protein belongs to the family of the small heat shock proteins and that it occurs also extra-lenticularly in many different cell types. AlphaB-Crystallin is mainly present in the cytoplasm, but there are some indications that it might have a function in the nucleus too. However, till now its presence in the nucleus is uncertain. We therefore compared the localization of alphaB-crystallin in nine cell lines cultured under normal conditions using four different antisera. All four antisera gave a diffuse staining for alphaB-crystallin in the cytoplasm, but one of the antibodies consistently showed nuclear staining in eight of the cell types, in the form of distinct speckles. These speckles are equally pronounced in the different cell types, whether or not cytoplasmic alphaB-crystallin is present. Preabsorption of the antiserum with alphaB-crystallin abolished the staining. Furthermore we demonstrate that if only minor amounts of alphaB-crystallin are present, the protein seems to be located exclusively in the nucleus. However, in case of higher amounts of protein, alphaB-crystallin is distributed between cytoplasm and nucleus. The nuclear alphaB-crystallin exists, like the cytoplasmic alphaB-crystallin, in non-phosphorylated and phosphorylated forms, is Triton-insoluble but can be extracted by 2 M NaCl. These data suggest that alphaB-crystallin might be bound to the nuclear matrix per se or to nuclear matrix proteins via other proteins. In agreement with other nuclear matrix proteins, nuclear alphaB-crystallin staining turns diffuse upon mitosis and leaves the chromosomes unstained. Double staining experiments revealed colocalization of alphaB-crystallin with the splicing factor SC35 in nuclear speckles, suggesting a role for alphaB-crystallin in splicing or protection of the splicing machinery.     

Distribution of activated calmodulin in the chloronema tip cells of the moss Funaria hygrometrica

Auxin (indole-3-acetic acid) regulates caulonema differentiation as a result of gradual transitional events in the chloronema tip cells in moss protonema. This auxin action in the moss Funaria hygrometrica involves a rapid influx of calcium ions from the extracellular medium. This investigation demonstrates spatial and temporal changes in calmodulin (CaM) activation (formation of Ca(2+)-CaM complex) in the chloronema tip cells subjected to auxin treatment. Photomicroscopic localisation of the fluorescence (excitation at 365 nm and emission of 397 nm) from the tricomplex of Ca(2+)-CaM with trifluoperazine (TFP, a blocker of Ca(2+)-CaM action) shows a tip to base (tip high) gradient of Ca(2+)-CaM in the chloronema tip cells. Comparison of Ca(2+)-CaM-TFP fluorescence over time in the chloronema tip cells of wild type Funaria with the response in an auxin overproducer mutant (86.1) and an auxin deficient mutant (87.13) reveals the involvement of auxin in calmodulin activation as a rapid response prior to cell differentiation.     

Sensory and biomechanical responses to ramp-controlled distension of the human duodenum

The aim of this study was to develop a new method for investigation of the relationship among the mechanical stimulus, the biomechanical properties, and the visceral perception evoked by volume/ramp-controlled distension in the human duodenum in vivo. An impedance planimetric probe for balloon distension was placed in the third part of the duodenum in seven healthy volunteers. Distension of the duodenum was done at infusion rates of 10, 25, and 50 ml/min. The pump was reversed when level 7 was reached on a visual analog scale ranging from 0 to 10. Distensions were done with and without the administration of the antimuscarinic drug butylscopolamine. The total circumferential tension (T(total)) and the passive circumferential tension (T(passive)) were determined from the distension tests without and with the administration of butylscopolamine, respectively. T(total) and T(passive) showed an exponential behavior as a function of strain (a measure of deformation). The active circumferential tension (T(active)) was computed as T(total)-T(passive) and showed a bell-shaped behavior as a function of strain. At low distension intensities, the intensity of sensation at 10 ml/min was significantly higher than that obtained at 25 and 50 ml/min. The coefficient of variation at the pain threshold for circumferential strain (average 4.34) was closer to zero compared with those for volume (8.72), pressure (31.22), and circumferential tension (31.55). This suggests that the mechanoreceptors in the gastrointestinal wall depend primarily on circumferential strain. The stimulus-response functions provided evidence for the existence of low- and high-threshold mechanoreceptors in the human duodenum. Furthermore, the data suggest that high-threshold receptors are nonadapting.     

Receptor protein tyrosine phosphatase mu expression as a marker for endothelial cell heterogeneity; analysis of RPTPmu gene expression using LacZ knock-in mice

The receptor-like protein tyrosine phosphatase mu (RPTPmu) belongs to the subfamily of meprin, A5, RPTPmu (MAM) domain-containing RPTPs, which are thought to play an important role in cell-cell adhesion mediated processes. The current study was designed to examine the expression pattern of RPTPmu in mice. We have generated RPTPmu-LacZ knock-in mice that express the beta-galactosidase (LacZ) reporter gene under the control of the RPTPmu promoter. LacZ expression patterns were analysed in embryos and adult mice by whole mount LacZ staining. Analysis of beta-galactosidase activity of heterozygous embryos and adult tissues revealed RPTPmu expression in endothelial cells of arteries and capillaries. In contrast, expression was virtually absent in endothelial cells of veins and in fenestrated endothelial cells in the adult liver and spleen. Moreover, RPTPmu expression was found in endothelial cells from the endocardium and the aorta in embryos, but not in adult mice. In addition to heterogeneous expression in endothelial cells, RPTPmu expression was found in cardiac muscle cells but not in skeletal muscle cells or smooth muscle cells. Expression was also found in Type II pneumonocytes in the lung alveoli and in Purkinje cells and other neurons in the brain. The specific expression of RPTPmu in arterial endothelial cells and in cardiac myocytes suggests that RPTPmu may play a role in the regulation of cardiovascular functions.     

Pluripotency deficit in clones overcome by clone-clone aggregation: epigenetic complementation?

Abnormal gene expression patterns in somatic cell clones and their attrition in utero are commonly considered a consequence of errors in nuclear reprogramming. We observe that mouse clone blastocysts have less than half the normal cell number, and that higher cell number correlates with correct expression of Oct4, a gene essential for peri-implantation development and embryonic pluripotency. To increase the cell number, we aggregated genetically identical clones at the 4-cell stage. Clone-clone aggregates did not form more blastocysts, but the majority expressed Oct4 normally and had higher rates of fetal and postnatal development. Fertilized blastocysts with low cell numbers, induced by removal of two blastomeres at the 4-cell stage, did not exhibit abnormal Oct4 expression, indicating that improved gene expression and post-implantation development of clone-clone aggregates is not a consequence of increased cell number. Rather, we propose that complementation of non-cell-autonomous defects of genetically identical, but epigenetically different, embryos results in improved gene expression in clone-clone aggregates.