In vitro evaluation of ablation parameters of normal and fibrous aorta using smooth excimer laser coronary angioplasty

A modified exeimer laser energy delivery system was used to irradiate 100 segments of normal and fibrous aorta in vitro. The laser beam was scanned into 8 fiber bundles consisting of 50 fibers each resulting in a reduction of the applied pulse energy. The total repetition rate was increased to 150 Hz in order to keep the repetition rate per fiber bundle close to 20 Hz and to minimize thermal injury. The results demonstrate that effective ablation (etch rate per 8 pulses > 2.0 μm) occurred at an energy fluency of 50 mJ/mm² in both normal and fibrous aorta. Tissue damage (carbonization, tissue separation, fissures, cracks, and vacuolization) was in a range of 100 ± 28 to 152 ± 30 μm for normal aorta and in a range of 57 ± 35 to 110 ± 39 μm for fibrous aorta. We conclude that effective ablation of normal and fibrous human aorta can be achieved by the application of smooth excimer laser coronary angioplasty. This improvement of excimer laser technology may result in a reduction of shock wave- and cavitation-induced damage leading to a reduction of tissue injury. However, this awaits further in vitro and in vivo confirmation. © 1993 Wiley-Liss, Inc.     

Korrektureingriffe am Fuß nach posttraumatischen ischämischen Kontrakturen

Operationsprinzip Korrektur eines Pes equinus adductus durch keilf?rmige Resektion des Chopart-Gelenkes mit Keilbasis dorsolateral. Bei gleichzeitigem Pes varus keilf?rmige Resektion des subtalaren Gelenkes mit Keilbasis lateral (Lange 1962 [7], Myerson et al. 1986 [8], Witt et al. 1985 [13]) (Abbildungen 1a bis 1f). Bei gleichzeitigem Tarsaltunnelsyndrom Dekompression des Nervus tibialis durch Spaltung des Retinaculum musculi flexorum. Zur Korrektur von Krallenzehen Resektion der jeweiligen distalen Grundphalangen nach Hohmann; bei flektierten Endgelenken Resektion der distalen Mittelphalangen. (Auf diese Techniken wird hier nicht eingegangen).      

First analysis of the proteome in two nematomorph species, Paragordius tricuspidatus (Chordodidae) and Spinochordodes tellinii (Spinochordodidae).

The proteome of most parasite species is currently unknown. Hairworms (Nematomorpha), 300 species distributed around the world, are parasitic in arthropods (mainly terrestrial species) when juveniles, but they are free-living in aquatic environments when adult. Most aspects of their systematics and biology are currently unknown. The aim of this paper was (i) to report a novel and reproducible protocol for the analysis of the proteome of hairworms using two-dimensional gel electrophoresis (2-DGE) and mass spectrometry (matrix laser desorption ionization-time of flight mass spectrometry (MALDI-TOF)) and (ii) to determine the level of proteomic divergence between two sympatric but taxonomically unrelated nematomorph species in the adult stage, Paragordius tricuspidatus Dufour (Nematomorpha, Gordiidae) and Spinochordodes tellinii Camerano (Nematomorpha, Gordiidae). In total, 689 protein spots were observed for P. tricuspidatus, 575 for S. tellinii. Only 36.2% spots were shared between the two species. Quantitative analysis of the proteins which are common to both parasite species reveals substantial differences in the pattern of protein expression. These results suggest a rapid evolutionary divergence between these two nematomorph families. Also, to test the value of our MALDI-TOF protocol, we used Actin-2 (Act-2), a protein highly conserved in the course of evolution. Peptide mass fingerprint (PMF) data obtained for Act-2 of P. tricuspidatus and S. tellinii suggest a very high homology with Act-2 of different worms species belonging to the Bilateria phylum (Annelida and Nematoda) and more specifically to Lumbricus terrestris (Annelida, Lumbricidae) and Caenorhabditis elegans (Nematoda, Rhabditidae). We discuss our results in relationship with current ideas concerning the use of proteomics in systematics.     

Kinesthetic sense of the shoulder in patients with impingement syndrome

A proprioceptive deficit is an important determinant of disability in various shoulder disorders, such as instability and osteoarthrosis. In 15 patients with impingement syndrome stage II (Neer 1983), who were treated by arthroscopic subacromial decompression, we measured movement sense by determining threshold levels for the perception of motion of the shoulder. The patients were placed in a specially designed chair allowing continuous passive motion of the shoulder joint, while avoiding cutaneous, auditory and visual stimuli. To assess movement detection thresholds, passive abduction movements of the shoulder were performed at a starting angle of 60°, an amplitude of 10° and an angular velocity of 1.3°/s. Before surgery, all patients had higher threshold levels for the perception of motion in their affected shoulders then in the other side. After decompression, proprioception had improved on the decompressed side, but was unchanged on the other side.     

Checklist for the qualitative evaluation of clinical studies with particular focus on external validity and model validity

Background  

It is often stated that external validity is not sufficiently considered in the assessment of clinical studies. Although tools for its evaluation have been established, there is a lack of awareness of their significance and application. In this article, a comprehensive checklist is presented addressing these relevant criteria.     

Effect of titanium surface texture on the cell-biomaterial interface.

To improve the in vivo performance of engineered implants, this study examines the independent effects of surface chemistry and topography on fibroblast morphology and density in vitro. Titanium (Ti) was sputter-coated onto smooth and microtextured polyethylene terephthalate (PET). Test specimens were evaluated in 24-h, fibroblast cultures and assessed with scanning electron microscopy (SEM) for cellular morphology and density. Fibroblast density increased, as the Ti film thickness increased. The fibroblasts exhibited contact guidance on the textured test specimens. The greatest cellular density was found on the Ti-coated, textured test specimens. In conclusion, Ti and surface texture appeared to strongly influence fibroblast density and morphology as compared to PET and smooth surfaces.     

k-t2 BLAST: exploiting spatiotemporal structure in simultaneously cardiac and respiratory time-resolved volumetric imaging.

Multidimensional imaging resolving both the cardiac and respiratory cycles simultaneously has the potential to describe important physiological interdependences between the heart and pulmonary processes. A fully five-dimensional acquisition with three spatial and two temporal dimensions is hampered, however, by the long acquisition time and low spatial resolution. A technique is proposed to reduce the scan time substantially by extending the k-t BLAST framework to two temporal dimensions. By sampling the k-t space sparsely in a lattice grid, the signal in the transform domain, x-f space, can be densely packed, exploiting the fact that large regions in the field of view have low temporal bandwidth. A volumetric online prospective triggering approach with full cardiac and respiratory cycle coverage was implemented. Retrospective temporal interpolation was used to refine the timing estimates for the center of k-space, which is sampled for all cardiac and respiratory time frames. This resulted in reduced reconstruction error compared with conventional k-t BLAST reconstruction. The k-t(2) BLAST technique was evaluated by decimating a fully sampled five-dimensional data set, and feasibility was further demonstrated by performing sparsely sampled acquisitions. Compared to the fully sampled data, a fourfold improvement in spatial resolution was accomplished in approximately half the scan time.     

Effects of graft pooling of foetal rat and mouse tissue and immunosuppression in the 6-hydroxydopamine rat model of Parkinson’s disease

 We employed intracerebral co-transplantation of foetal xenogeneic striatal mouse tissue and allogeneic rat substantia nigra into the adult rat brain to elucidate the effects of xenogeneic mouse graft on the function and survival of an allogeneic rat graft in 6-hydroxydopamine lesioned Sprague-Dawley rats. Foetal mouse striatum (STR) and rat substantia nigra (VM) were transplanted as non-pooled separate deposits or a pooled cell suspension with or without cyclosporin A (Cy A). Immunosuppressed recipients of pooled rat and mouse co-grafts showed a significantly better compensation of amphetamine-induced rotational behaviour compared with non-immunosuppressed animals with pooled rat and mouse co-grafts 3 and 6 weeks post-grafting.Tyrosine hydroxylase (TH) immunohistochemistry revealed a non-significant reduction in survival in pooled (1806.3±367.5 cells) rat and mouse co-transplants without immunosuppression compared with immunosuppressed pooled (3383.3±732.7 cells) animals with allo- and xenogeneic tissue and controls (3506.4±839.3 cells). Graft volumes were significantly reduced in pooled transplants without immunosuppression (0.1±0.026 mm³; ANOVA post-hoc SchefféF-test, P<0.0001) compared with immunosuppressed recipients (0.7±0.1 mm³) and controls (0.6±0.1 mm³). In non-pooled allo- and xenogeneic grafts without immunosuppression the survival rate of the TH-immunoreactive cells and graft volumes were reduced (2359.3±479.5 cells; 0.2±0.043 mm³) compared with immunosuppressed animals (2927.3±946.6 cells; 0.6±0.2 mm³) and controls (2701.1±693.8 cells; 0.3±0.1 mm³) without reaching a level of significance. Rejection of mouse tissue was observed in all non-immunosuppressed recipients. In summary: (i) continued immunosuppression yielded significant beneficial effects on function and beneficial effects on survival of pooled grafts with an immunogenetic disparity; (ii) the rejection of a xenogeneic graft component may compromise survival and function of other, allogeneic graft components; and (iii) transplantation of non-pooled allo- and xenogeneic tissues may result in a better survival of the graft compared with pooled cell suspensions. Received: 25 March 1996 / Accepted: 1 December 1996     

Poverty and health in West Germany

Summary The relationship between poverty and several health-related characteristics in West Germany was investigated. Data were derived from the National and Regional Health Surveys conducted in West Germany from 1984 to 1992. 25544 males and 25719 females with German nationality aged 25–69 years were examined. Poverty was defined as a household income of 50% less than the mean for West Germany. Multiple logistic regression analysis was used to analyze the relationship between poverty and four health variables: individual health behavior, subjective assessment of health status, cardiovascular disease risk factors, and self-reported prevalence of lifetime chronic diseases. 10.2% of males and 12.8% of females were classified as being below the poverty line. For most but not all health parameters, less favourable results were found for the segment of the population with a household income below the poverty line. The most striking poverty-related differences were observed for lack of regular sport activities, subjective health satisfaction, obesity and myocardial infarction/stroke. Significantly lower prevalence rates for study subjects below the poverty line were observed for hypercholesterolemia in females only. Allergic disorders were the only chronic diseases reported significantly less often in males and females below the poverty line. Poverty has strong effects on individual health status and the prevalence of chronic diseases. Due to the rising unemployment rates in Germany in the last years it is very likely that the strong negative consequences of poverty for health are increasing.

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Zusammenfassung Es wird untersucht, welche Zusammenhänge zwischen Armut und verschiedenen gesundheitsbezogenen Merkmalen bestehen. Datenbasis sind die nationalen und regionalen Gesundheitssurveys, die in den Jahren 1984 bis 1992 in Westdeutschland durchgeführt wurden. 25544 Männer und 25719 Frauen mit deutscher Nationalität im Alter von 25 bis 69 Jahren wurden einbezogen. Armut wurde definiert als ein Haushaltseinkommen, das um 50% niedriger ist als das mittlere Einkommen in Westdeutschland. Die statistische Auswertung erfolgte mittels multipler logischer Regressionsanalyse, 10,2% der Männer und 12,8% der Frauen hatten ein Haushaltseinkommen unterhalb der Armutsgrenze. Die ausgeprägtesten armutsbezogenen Unterschiede wurden beobachtet für den Mangel an körperlicher Bewegung, die subjektive Gesundheitszufriedenheit, das starke. Übergewicht und die kardiovaskulären Krankheiten. Signifikant niedrigere Prävalenzen für Personen mit Einkommen unterhalb der Armutsgrenze ergaben sich bei den Frauen für den Risikofaktor Hypercholesterinämie. Allergien waren die einzige chronische Krankheit, die bei beiden Geschlechtern signifikant seltener in der von Armut betroffenen Bevölkerungsgruppe berichtet wurde. Vor dem Hintergrund der in den letzten Jahren stark angestiegenen Arbeitslosigkeit in Deutschland ist zu befürchten, dass die negativen Konsequenzen der Armut für die gesundheitliche Lage deutlich zugenommen haben.

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Résumé Les rapports entre pauvreté et differents indices sanitaires ont été examinés. Les donnees proviennent des surveys de santé nationales et régionales, réalisées en Allemagne de l'Ouest durant les années 1984 à 1992. 25719 femmes et 25544 hommes de nationalité allemande entre 25 et 69 ans ont paticipé. Le seuil de pauvreté a été fixé à un revenu égal a 50% du revenu moyen en Allemagne de l'Ouest. On a analysé les indices sanitaires suivants: le comportement sanitaire individuell, l'auto-estimation de sa santé, les facteurs de risque cardio-vasculaires et la prévalence des maladies chroniques. L'analyse statistique a été réalisée par regression logique multiple. 12,8% des femmes et 10,2% des hommes avaient un revenu inferieur au seuil de pauvreté. Pour la majorité des indices sanitaires on a trouvé des résultats défavorables pour la groupe ayant un revenu au dessous du seuil de pauvreté. Le manque de mouvement, l'auto-estimation de sa santé, l'excés de poids et les maladies cardio-vasculaires sont les indices quid diffèrent, relatif à la pauvreté, le plus. Les femmes ayant un revenu au-dessous du seuil de pauvreté ont des pourcentages de prévalence inférieurs significatifs pour le facteur de risque hypercholestérolémie. Les allergies sont les seules maladies qui existent significativement moins souvent chez les deux sexes de la groupe des pauvres. En résumé, la pauvreté présente un désavantage pour la santé individuelle et la prévalence des maladies chroniques. Sachant que le taux de chômage s'est aggravé pendant les dernières années, il est à craindre que les effets négatifs de la pauvreté sur la situation sanitaire ont nettement augmenté.

     

Genotypic selection of mutated DNA sequences using mismatch cleavage analysis, a possible basis for novel mutation assays

A novel technique for the selection of mutated DNA sequences,termed mismatch cleavage-polymerase chain reaction (MC-PCR),is proposed. The method is based on hybridizing genomic DNAwith a suitable probe, several 100 bp long. Mutated DNA sequenceswill form mismatched heteroduplexes which are cleaved by usingresolvases. Cleaved heteroduplexes are detected by ligationto an oligonucleotide adaptor and then amplified by using PCR.If practical, this technique would have considerable advantagesover the restriction site mutation (RSM) method. Failure toachieve cleavage efficiencies of close to 100% will not compromisesuccess. This is because positive signals (PCR amplification)arise from cleaved mutated sites and not, as in RSM, from DNAsequences resistant to cleavage by restriction endonucleases.Furthermore, the mutational target is much larger than in RSM.It would be possible to screen stretches of DNA several 100bp in length for mutations. Any mutation, independent of itslocation, could be identified. The usefulness of MC-PCR forthe genotypic selection of mutants will depend on the effectivenesswith which a small number of mismatched heteroduplexes can berecognized, cleaved and ligated. ¹To whom correspondence should be addressed