The water jet as a new tool for endoprosthesis revision surgery--an in vitro study on human bone and bone cement

In revision surgeries of endoprostheses, the interface between implant and bone cement or bone must be loosened. Conventional tools have many disadvantages because of their size and limited range. Taking advantage of the selective and athermic cutting process, a plain water jet is already used in order to cut soft tissues. This study investigates the possibilities of both a plain and an abrasive water jet as cutting tools for revision surgery. Samples of the mid-diaphysis of human femora and bone cement (CMW3) were cut with a plain water jet (PWJ) and an abrasive water jet (AWJ) at two different jet-to-surface angles (30 degrees,90 degrees ) and at five different pressure levels (30, 40, 50, 60, 70 MPa). For a PWJ a selective pressure range was identified, where only bone cement was cut. Injecting a bio-compatible abrasive (lactose) to the jet stream resulted in significantly higher cut depths in both materials. Material removal in bone was significantly less at the smaller jet-to-surface angle for both techniques. No clear selectivity between bone and bone cement was observed for application of the AWJ. However, the material removal rate was significantly higher for bone cement than for bone at all pressure levels. The results indicate that an AWJ might be an alternative tool for cement removal. The possibility for localised cutting at interfaces could be an advantage for revision of a non-cemented prosthesis.     

Two independent mutations in a family with neurofibromatosis type 1 (NF1)

We report on two independent alterations of the NF1 gene in a three-generation kindred with neurofibromatosis type 1 (NF1). Using temperature gradient gel electrophoresis (TGGE) in a mutation analysis of exon 31 of the NF1 gene we detected the previously reported nonsense mutation R1947X. This C-to-T transition at codon 1947 in exon 31 is considered to represent a mutation "hot spot" of the NF1 gene due to 5mCpG deamination. All living family members together with their genomic DNA were included in this investigation. However, the mutation R1947X was absent from two undoubtedly affected siblings of the propositus. Another NF1 mutation (889-2A-->G) was identified in the two sibs by the protein truncation test (PTT). The novel splice site mutation 889-2A-->G results in a skip of NF1 exon 7 during splicing and protein truncation due to frameshift. The two NF1 alterations are linked to different paternal haplotypes. In our study of a three-generation kindred, R1947X represents a de novo mutation whereas 889-2A-->G is an inherited splice mutation. Implications for phenotype variation are discussed.     

Induction of NO synthesis in macrophages by Newcastle disease virus is associated with activation of nuclear factor-{kappa}B

Newcastle disease virus (NDV) has received much attention recentlybecause of its non-specific immune stimulating potential andits various anti-tumor activities. Here we describe that NDVinduces synthesis of NO and causes an activation of nuclearfactor-kB (NF-kB) In murine macrophages. These reactions werepart of an activation process which included also stimulationof adenosine deaminase and inhibition of 5'-nucleotidase. NDV-mediatedNO synthesis and NF-kB activation were blocked by an antioxidant(butylated hydroxyanisole), by an inhibitor of protein tyrosinekinase (genistein) and of protein kinase A (H-89), but not byan inhibitor of protein kinase C (staurosporin). These datasuggest that signalling requirements of NF-kB activation andNO production in NDV-treated macrophages are similar.     

Skill needs for nurses in their role as health informatics professionals: a survey in the context of global health informatics education

In the process of developing global health informatics education, a common understanding of educational outcomes is required. Therefore, an educational framework for health informatics professionals is desirable to support student mobility, trans-national and borderless education. Nurses form a significant part of the health workforce and need to be properly educated for their roles in health informatics. To ascertain their perceptions of needs and priorities, we developed a web-based questionnaire and surveyed Australian nurses on the preferred knowledge/skills set for health informatics professionals. Among others, the questionnaire is based on the International Medical Informatics Association's (IMIA) set of recommendations on education and IMIA's scientific map. Benner's five levels of competencies were applied to measure the degree of competency required for each skill/knowledge. Altogether, 82 Australian nurses completed the questionnaire. The nurses' perceived degree of competency required for a total of 74 specific skills and knowledge in five skill categories is presented in this paper as well as the overall results for each of the five categories. Further, significant differences between the nurses' primary roles and primary interest in health informatics are discussed. The development of a comprehensive health informatics education framework needs to take into account nurses as well as other health professionals. Repeating the survey in other countries and for various professions is essential to develop an international educational framework.     

T cell reactivity in neonates from an East and a West German city--results of the LISA study

BACKGROUND: Within an ongoing birth cohort study (LISA) the cytokine production of cord blood T cells was compared between neonates from Leipzig (East Germany) and Munich (West Germany). The aim of this study was to analyse regional differences and influencing factors of the immune status. METHODS: Cytokine production was measured in a randomly selected subgroup of 158 children from the LISA (Life style - Immune system - Allergy) cohort by intracellular cytokine staining. Information on family "atopy" history (FAH) and home characteristics was obtained from questionnaires. RESULTS: Reduced numbers of interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) producing T cells were found in association with biparental FAH and housing renovation during pregnancy. In addition, cytokine production was influenced by season. In Munich, the frequency of biparental FAH and of renovation measures during pregnancy was significantly higher as compared to Leipzig. Neonates from Munich showed significantly decreased amounts of IFN-gamma and TNF-alpha and elevated levels of interleukin-4 (IL-4) producing T cells. Differences in cytokine production between Munich and Leipzig were influenced by season (IL-4) and housing renovation (IFN-gamma, TNF-alpha). CONCLUSIONS: Since differences in the T cell cytokine production of neonates in Munich and Leipzig are independent from FAH our findings may provide evidence for the impact of environmental factors upon the fetal immune system.     

Age-related changes in peripheral nerves

Semi-thin sections of the sural nerve from 200 autopsy specimens taken from individuals of both sexes, ages 10 to 91 were morphologically examined. Thickness of the endoneurial capillary walls, and of the perineurium, number of endoneurial capillaries, myelinated fiber density and distribution of myelinated fibers were determined. An additional ultrastructural examination of selected nerves with characteristic values was performed. The analysis revealed a statistically significant age dependence for the investigated features. Increasing age was associated with decreased myelinated fiber density and decreased number of endoneurial capillaries. There was an age dependent increase in the thickness of capillary walls and the perineurium as well as increasing loss of large myelinated fibers. The findings were discussed and compared with similar results from the literature. Age related changes in peripheral nerves have to be interpreted as the result of the cumulative, life-long effect of various pathogenic factors, modified by genetic determinants and by a gradual decrease in regenerative capacity.     

Test-ordering by multiple physicians increases unnecessary laboratory examinations

In modern teaching hospitals, patients typically receive direct care from a succession of different physicians, each of whom may order diagnostic tests on the same patient. We examined the association of test-ordering by multiple physicians with unnecessary duplication of 20-test chemistry profiles in 198 consecutively admitted patients. In a multivariate regression model, the number of duplicate chemistry profiles ordered for a patient was significantly correlated with the number of physicians ordering profiles after controlling for the overall intensity of profile testing. In a case-control analysis comparing duplicate with nonduplicate profiles, redundant tests were significantly more likely to have been ordered by a new physician who had not ordered a patient's previous profile than by the same physician who had ordered the previous chemistry panel. We conclude that test ordering by multiple physicians, the prevalent pattern in almost all teaching hospitals, predisposes to unnecessary laboratory examinations.     

Importance of immunohistochemistry for neuro-oncology. IV. Distribution model of beta human chorionic gonadotropins in intracranial germ cell tumors

beta-Human choriogonadotropic hormone (beta-HCG) is considered a good marker for trophoblastic differentiation of germ cell tumors. 34 primary intracranial germ cell tumors (15 germinomas, 6 mature teratomas, 1 embryonal carcinoma, 2 endodermal sinus tumors and 10 mixed germ cell tumors) were immunohistochemically evaluated for the presence of beta-HCG positive cells. In 8 of 15 germinomas and 6 of 10 mixed germ cell tumors beta-HCG cells were demonstrable. In the germinomas such cells included both syncytiotrophoblastic and mononuclear cells which histologically did not correspond to the cytotrophoblast. In one case the patient had exhibited a precocious puberty. Of the 6 beta-HCG positive mixed germ cell tumors, two contained elements of choriocarcinoma. In the cytotrophoblasts of the choriocarcinoma regions, beta-HCG was only sparsely demonstrable. Both of these patients had manifest precocious puberty clinically. The advantage of immunohistochemical demonstration of the beta-HCG compared to conventional histology is in the definite identification of trophoblastic differentiation, in particular the exact recognition of the choriocarcinoma segments, which can be critical for the prognosis. Demonstration of isolated syncytiotrophoblasts and beta-HCG positive mononuclear cells in the seminomas is of no prognostic significance and is primarily of theoretical interest.     

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