170 research outputs found

    An investigation of the relation between cooperation and the innovative success of German regions

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    Concepts like regional innovation systems, innovative milieu, and learning regions emphasize the positive contribution of intra-regional cooperation to firmsÕ innovation performance. Despite substantial numbers of case studies, the quantitative empirical evidence for this claim is thin. Using data on the co-application and co- invention of patents for 270 German labor market regions the study shows that intra- regional cooperation intensity and regional innovation efficiency are associated. In contrast to the negative influence of inter-regional cooperation, medium levels of intra-regional cooperation stimulate regional innovation efficiency.regional innovation efficiency, cooperation intensity, collaboration, regional cooperation

    The influence of polymorbidity, revascularization, and wound therapy on the healing of arterial ulceration

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    Joerg Tautenhahn1, Ralf Lobmann2, Brigitte Koenig3, Zuhir Halloul1, Hans Lippert1, Thomas Buerger11Department of General, Visceral and Vascular Surgery; 2Department of Endocrinology and Metabolism; 3Institute for Medical Microbiology, Medical School, Otto-von-Guericke University, Magdeburg, GermanyObjective: An ulcer categorized as Fontaine’s stage IV represents a chronic wound, risk factor of arteriosclerosis, and co-morbidities which disturb wound healing. Our objective was to analyze wound healing and to assess potential factors affecting the healing process.Methods: 199 patients were included in this 5-year study. The significance levels were determined by chi-squared and log-rank tests. The calculation of patency rate followed the Kaplan-Meier method.Results: Mean age and co-morbidities did not differ from those in current epidemiological studies. Of the patients with ulcer latency of more than 13 weeks (up to one year), 40% required vascular surgery. Vascular surgery was not possible for 53 patients and they were treated conservatively. The amputation rate in the conservatively treated group was 37%, whereas in the revascularizated group it was only 16%. Ulcers in patients with revascularization healed in 92% of cases after 24 weeks. In contrast, we found a healing rate of only 40% in the conservatively treated group (p < 0.001). Revascularization appeared more often in diabetic patients (n = 110; p < 0.01) and the wound size and number of infections were elevated (p = 0.03). Among those treated conservatively, wound healing was decelerated (p = 0.01/0.02; χ² test).Conclusions: The success of revascularization, presence of diabetes mellitus, and wound treatment proved to be prognostic factors for wound healing in arterial ulcers.Keywords: arterial leg ulcer, wound management, risk factors, revascularizatio

    Genetic Variants in ARHGEF6 Cause Congenital Anomalies of the Kidneys and Urinary Tract in Humans, Mice, and Frogs

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    Background About 40 disease genes have been described to date for isolated congenital anomalies of the kidneys and urinary tract (CAKUT), the most common cause of childhood chronic kidney disease. However, these genes account for only 20% of cases. ARHGEF6, a guanine nucleotide exchange factor that is implicated in such biologic processes as cell migration and focal adhesion, acts downstream of integrin linked kinase (ILK) and parvin proteins. A genetic variant of ILK that causes murine renal agenesis abrogates the interaction of ILK with a murine focal adhesion protein encoded by Parva, leading to CAKUT in mice with this variant. Methods To identify novel genes that, when mutated, result in CAKUT, we performed exome sequencing in an international cohort of 1265 families with CAKUT. We also assessed the effects in vitro of wild-type and mutant ARHGEF6 proteins, as well as the effects of Arhgef6 deficiency in mouse and frog models. Results We detected six different hemizygous variants in the gene ARHGEF6 (which is located on the X chromosome in humans) in eight individuals from six families with CAKUT. In kidney cells, overexpression of wild-type ARHGEF6-but not proband-derived mutant ARHGEF6- increased active levels of CDC42/RAC1, induced lamellipodia formation, and stimulated PARVAdependent cell spreading. ARHGEF6 mutant proteins showed loss of interaction with PARVA. Three-dimensional MDCK cell cultures expressing ARHGEF6 mutant proteins exhibited reduced lumen formation and polarity defects. Arhgef6 deficiency in mouse and frog models recapitulated features of human CAKUT. Conclusions Deleterious variants in ARHGEF6 may cause dysregulation of integrin-parvinRAC1/CDC42 signaling, thereby leading to X-linked CAKUT

    The assessment of angiogenesis and fibroblastic stromagenesis in hyperplastic and pre-invasive breast lesions

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    <p>Abstract</p> <p>Background</p> <p>To investigate the changes of the neoplastic microenvironment during the different morphological alterations of hyperplastic and pre-invasive breast lesions.</p> <p>Methods</p> <p>78 in situ ductal carcinomas of all degrees of differentiation, 22 atypical ductal hyperplasias, 25 in situ lobular carcinomas, 18 atypical lobular hyperplasias, 32 ductal epithelial hyperplasias of usual type and 8 flat atypias were immunohistochemically investigated for the expression of vascular endothelial growth factor (VEGF), smooth muscle actin (SMA) and CD34, while microvessel density (MVD) was counted using the anti-CD31 antibody.</p> <p>Results</p> <p>VEGF expression was strongly correlated with MVD in all hyperplastic and pre-invasive breast lesions (p < 0.05). Stromagenesis, as characterized by an increase in SMA and a decrease in CD34 positive myofibroblasts was observed mostly around ducts harboring high grade in situ carcinoma and to a lesser extent around moderately differentiated DCIS. In these two groups of in situ carcinomas, a positive correlation between MVD and SMA (p < 0.05) was observed. On the contrary, CD34 was found to be inversely related to MVD (p < 0.05). No statistically significant changes of the stromal fibroblasts were observed in low grade DCIS neither in any of the other lesions under investigation as compared to normal mammary intra- and interlobular stroma.</p> <p>Conclusion</p> <p>Angiogenesis is observed before any significant fibroblastic stromagenesis in pre-invasive breast lesions. A composite phenotype characterized by VEGF positive epithelial cells and SMA positive/CD34 negative stromal cells, is identified mostly in intermediate and high grade DCIS. These findings might imply for new therapeutic strategies using both anti-angiogenic factors and factors selectively targeting tumor stroma in order to prevent the progression of DCIS to invasive carcinoma.</p

    HIF1-alpha overexpression indicates a good prognosis in early stage squamous cell carcinomas of the oral floor

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    BACKGROUND: Hypoxia-inducible factor 1 (HIF-1) is a transcription factor, which plays a central role in biologic processes under hypoxic conditions, especially concerning tumour angiogenesis. HIF-1α is the relevant, oxygen-dependent subunit and its overexpression has been associated with a poor prognosis in a variety of malignant tumours. Therefore, HIF-1α expression in early stage oral carcinomas was evaluated in relation to established clinico-pathological features in order to determine its value as a prognostic marker. METHODS: 85 patients with histologically proven surgically treated T1/2 squamous cell carcinoma (SCC) of the oral floor were eligible for the study. Tumor specimens were investigated by means of tissue micro arrays (TMAs) and immunohistochemistry for the expression of HIF-1. Correlations between clinical features and the expression of HIF-1 were evaluated by Kaplan-Meier curves, log-rank tests and multivariate Cox regression analysis. RESULTS: HIF-1α was frequently overexpressed in a probably non-hypoxia related fashion. The expression of HIF-1α was related with a significantly improved 5-year survival rate (p < 0.01) and a significantly increased disease free period (p = 0.01) independent from nodal status and tumour size. In primary node negative T1/T2 SCC of the oral floor, absence of HIF-1α expression specified a subgroup of high-risk patients (p < 0.05). CONCLUSION: HIF-1α overexpression is an indicator of favourable prognosis in T1 and T2 SCC of the oral floor. Node negative patients lacking HIF-1α expression may therefore be considered for adjuvant radiotherapy

    Cytokeratin 8/18 expression indicates a poor prognosis in squamous cell carcinomas of the oral cavity

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    BACKGROUND: Intermediary filaments are involved in cell motility and cancer progression. In a variety of organs, the expression of distinct intermediary filaments are associated with patient prognosis. In this study, we seeked to define the prognostic potential of cytokeratin and vimentin expression patterns in squamous cell carcinomas (SCC's) of the oral cavity. METHODS: 308 patients with histologically proven and surgically treated squamous cell carcinomas of the oral cavity were investigated for the immunohistochemical expression of a variety of intermediary filaments including high- and low-molecular weight cytokeratins (Ck's), such as Ck 5/6, Ck 8/18, Ck 1, CK 10, Ck 14, Ck 19 and vimentin, using the tissue microarray technique. Correlations between clinical features and the expression of Cytokeratins and vimentin were evaluated statistically by Kaplan-Meier curves and multivariate Cox regression analysis. RESULTS: The expression of Ck 8/18 and Ck 19 were overall significantly correlated with a poor clinical prognosis (Ck 8/18 p = 0.04; Ck19 p < 0.01). These findings could also be reproduced for Ck 8/18 in primary nodal-negative SCC's and held true in multivariate-analysis. No significant correlation with patient prognosis could be found for the expression of the other cytokeratins and for vimentin. CONCLUSION: The expression of Ck 8/18 in SCC's of the oral cavity is an independent prognostic marker and indicates a decreased overall and progression free survival. These results provide an extended knowledge about the role of intermediary filament expression patterns in SCC's

    High incidence of metastatic disease in primary high grade and large extremity soft tissue sarcomas treated without chemotherapy

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    BACKGROUND: The risk of metastasis and the survival in patients with primary extremity soft tissue sarcomas is worse when tumour size is large and the grade of malignancy is high. Such tumours may receive chemotherapy and/or radiation therapy (RTX) for optimising local control. Irradiation can either be applied preoperatively or after tumour resection. The question arises if the kind of RTX in the absence of chemotherapy influences the outcome concerning local control, metastatic disease, survival and complications. METHODS: We retrospectively reviewed the clinical outcome of 233 patients with a primary extremity soft tissue sarcoma treated between 1990 – 2000 with a mean follow-up of 35.8 (4–120) months in our institute. 41 patients had high grade, deep and large tumours (>8 cm), an AJCC stage III (no evidence of metastasis prior to treatment) and were treated with limb salvage surgery and irradiation but stayed without additional chemotherapy. Two groups of patients were compared: the first group received postoperative RTX after tumour resection (n = 33); the second group was treated with preoperative RTX (n = 8). Both groups did not differ concerning clinical parameters. We analysed primary and secondary outcomes. RESULTS: 56% (23/41) of the population developed metastatic disease, 24% (10/41) local recurrence. The risk of metastasis was higher in the group with preoperative irradiation (p = 0.046). The overall (p = 0.0248) and relapse free survival (p = 0.104) were worse in this group. The delay to tumour resection amounted 8 weeks on average in the preoperative group. Local control was not different (p = 0.38) in both study groups. Wound infections and other combined therapy related complications were equally distributed (p = 0.22). CONCLUSION: Without chemotherapy there remains a high risk of metastasis in AJCC grade 3 patients. In high risk patients treated without chemotherapy the elapsed time to tumour resection after preoperative radiation might contribute to the development of metastasis. This outcome may support the thesis that a combination of RTX and offensive multimodal treatment protocols is advantageous in such a subset of patient

    The comorbidity profiles and medication issues of patients with multiple system atrophy:a systematic cross-sectional analysis

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    BACKGROUND: Multiple system atrophy (MSA) is a complex and fatal neurodegenerative movement disorder. Understanding the comorbidities and drug therapy is crucial for MSA patients' safety and management.OBJECTIVES: To investigate the pattern of comorbidities and aspects of drug therapy in MSA patients.METHODS: Cross-sectional data of MSA patients according to Gilman et al. (2008) diagnostic criteria and control patients without neurodegenerative diseases (non-ND) were collected from German, multicenter cohorts. The prevalence of comorbidities according to WHO ICD-10 classification and drugs administered according to WHO ATC system were analyzed. Potential drug-drug interactions were identified using AiDKlinik®.RESULTS: The analysis included 254 MSA and 363 age- and sex-matched non-ND control patients. MSA patients exhibited a significantly higher burden of comorbidities, in particular diseases of the genitourinary system. Also, more medications were prescribed MSA patients, resulting in a higher prevalence of polypharmacy. Importantly, the risk of potential drug-drug interactions, including severe interactions and contraindicated combinations, was elevated in MSA patients. When comparing MSA-P and MSA-C subtypes, MSA-P patients suffered more frequently from diseases of the genitourinary system and diseases of the musculoskeletal system and connective tissue.CONCLUSIONS: MSA patients face a substantial burden of comorbidities, notably in the genitourinary system. This, coupled with increased polypharmacy and potential drug interactions, highlights the complexity of managing MSA patients. Clinicians should carefully consider these factors when devising treatment strategies for MSA patients.</p

    The comorbidity and co-medication profile of patients with progressive supranuclear palsy

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    BackgroundProgressive supranuclear palsy (PSP) is usually diagnosed in elderly. Currently, little is known about comorbidities and the co-medication in these patients.ObjectivesTo explore the pattern of comorbidities and co-medication in PSP patients according to the known different phenotypes and in comparison with patients without neurodegenerative disease.MethodsCross-sectional data of PSP and patients without neurodegenerative diseases (non-ND) were collected from three German multicenter observational studies (DescribePSP, ProPSP and DANCER). The prevalence of comorbidities according to WHO ICD-10 classification and the prevalence of drugs administered according to WHO ATC system were analyzed. Potential drug-drug interactions were evaluated using AiDKlinik (R).ResultsIn total, 335 PSP and 275 non-ND patients were included in this analysis. The prevalence of diseases of the circulatory and the nervous system was higher in PSP at first level of ICD-10. Dorsopathies, diabetes mellitus, other nutritional deficiencies and polyneuropathies were more frequent in PSP at second level of ICD-10. In particular, the summed prevalence of cardiovascular and cerebrovascular diseases was higher in PSP patients. More drugs were administered in the PSP group leading to a greater percentage of patients with polypharmacy. Accordingly, the prevalence of potential drug-drug interactions was higher in PSP patients, especially severe and moderate interactions.ConclusionsPSP patients possess a characteristic profile of comorbidities, particularly diabetes and cardiovascular diseases. The eminent burden of comorbidities and resulting polypharmacy should be carefully considered when treating PSP patients
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