Flexible (Polyactive®) versus rigid (hydroxyapatite) dental implants

In a beagle dog study, the peri-implant bone changes around flexible (Polyactive®) and rigid hydroxyapatite (HA) implants were investigated radiographically by quantitative digital subtraction analysis and by assessment of marginal bone height, with the aid of a computerized method. A loss of approximately 1 mm of marginal bone height was observed for both the dense Polyactive and the HA implants, after 6 months of loading. This value appeared to be stable from 12 weeks of loading onward. Along the total length of the implant during the first 6 weeks of loading, both the flexible (dense Polyactive) and the rigid (HA) implants showed a decrease in density. However, after this 6-week period, the bone density around the implants increased, and after 18 weeks the original bone density was reached. The flexible Polyactive implants provoked less decrease in density than the rigid HA implants, although not to a statistically significant level. This finding sustains the hypothesis that flexible implant materials may transfer stresses to the surrounding bone more favorably

Targeting growth rate of abdominal aortic aneurysm

This thesis focuses on growth inhibition of small abdominal aortic aneurysms (AAA), which is a potentially lethal, pathological dilatation of 30 mm or more of the infrarenal aorta. The main clinical challenges are currently: Can we predict aneurysm growth? Is it possible to keep small aneurysms small? Can we translate the preclinical evidence into a medical therapy? On theoretical grounds and preclinical data, doxycycline appears an excellent lead-candidate for the medical stabilization of growing AAA. However, this randomized placebo controlled multicentre trial revealed that doxycycline treatment did not inhibit aneurysm progression but increased the growth rate. These highly remarkable findings fundamentally challenge the current paradigm that inflammation per se is harmful in AAA progression. In this context, other findings of this thesis gain importance, showing that patients with diabetes mellitus have slower aneurysm growth and that aneurysm patients are more likely to develop COPD. The responsible pathophysiological mechanisms contain undoubtedly important clues, but have to be unraveled yet.ZonMw, NutsOhraUBL - phd migration 201

Overzicht dioxine proeven uitgevoerd in Nederland met koeien en schapen

De problemen met dioxinen en dibenzofuranen in koeien en schapen in de omgeving van de Afvalverwerking Rijnmond (Lickebaert gebied 1985-1990) en de contaminatie van citruspulp (1998-1999) hebben aanleiding gegeven tot een aantal proeven. In deze notitie worden de belangrijkste gegevens van deze proeven samengevat. Doel van dit overzicht is om de huidige kennis en kennishiaten met betrekking tot risico's van overdracht van dioxine-achtige verbindingen naar het dierlijk product melk (en vlees) in kaart te brenge

Systematic approach towards reliable estimation of abdominal aortic aneurysm size by ultrasound imaging and CT

Background: The management of abdominal aortic aneurysm (AAA) is fully dictated by AAA size, but there are no uniform measurement guidelines, and systematic differences exist between ultrasound- and CT-based size estimation. The aim of this study was to devise a uniform ultrasound acquisition and measurement protocol, and to test whether harmonization of ultrasound and CT readings is feasible. Methods: A literature review was undertaken to evaluate evidence for ultrasound-based measurement of AAA. A protocol for measuring AAA was then developed, and intraobserver and interobserver reproducibility was tested. Finally, agreement between ultrasound readings and CT-based AAA diameters was evaluated. This was an observational study of patients with a small AAA who participated in two pharmaceutical intervention trials. Results: Based on a literature review, an ultrasound acquisition and reading protocol was devised. Evaluation of the protocol showed an intraobserver repeatability of 1.6 mm (2s.d.) and an interobserver intraclass correlation coefficient (ICC) of 0.97. Comparison of protocolled ultrasound readings and local CT readings indicated a good correlation (r = 0.81), but a systematic +4.1-mm difference for CT. Harmonized size readings for ultrasound imaging and CT increased the correlation (r = 0.91) and reduced the systematic difference to +1.8 mm by CT. Interobserver reproducibility of protocolized CT measurements showed an ICC of 0.94 for the inner-to-inner method and 0.96 for the outer-to-outer method. Conclusion: The absence of harmonized size acquisition and reading guidelines results in overtreatment and undertreatment of patients with AAA. This can be avoided by the implementation of standardized ultrasound acquisition and a harmonized reading protocol for ultrasound- and CT-based readings

Identification of a nonsense mutation in the granulocyte-colony-stimulating factor receptor in severe congenital neutropenia

Severe congenital neutropenia (Kostmann syndrome) is characterized by profound absolute neutropenia and a maturation arrest of marrow progenitor cells at the promyelocyte-myelocyte stage. Marrow cells from such patients frequently display a reduced responsiveness to granulocyte-colony-stimulating factor (G-CSF). G-CSF binds to and activates a specific receptor which transduces signals critical for the proliferation and maturation of granulocytic progenitor cells. Here we report the identification of a somatic point mutation in one allele of the G-CSF receptor gene in a patient with severe congenital neutropenia. The mutation results in a cytoplasmic truncation of the receptor. When expressed in murine myeloid cells, the mutant receptor transduced a strong growth signal but, in contrast to the wild-type G-CSF receptor, was defective in maturation induction. The mutant receptor chain may act in a dominant negative manner to block granulocytic maturation

Kengetallen van enkele landbouwhuisdieren en hun consumptiepatronen

De dierlijke produtieketen bestaat uit diverse schakels, waarbij een grote reeks plantaardige producten de basis voor de dierlijke producten vormen. Er zijn een aantal typen basisgegevens noodzakelijk om de relatie te kunnen onderzoeken tussen de kwaliteit van de plantaardige voedermiddelen en de kwaliteit van de dierlijke producten,. Deze gegevens betreffen de omvang van de dagelijkse consumptie van diervoeding door het dier en de samenstelling van het dagelijkse voedselpakket. Daarnaast is informatie noodzakelijk over de omvang van de dierlijke productie, hetzij dagelijks (melk, eieren, aandeel vet), hetzij aan het einde van de levensduur (organen, spier, aandeel vet). In dit rapport zijn genoemde gegevens verzameld voor elf diercategorieën: melkvee, varkens (startvoer, en mengvoeders voor vleesvarkens van 40 tot 105 kg lichaamsgewicht met resp. een lage en een hoge energiewaarde), fokzeugen in de fase van dracht en van lactatie, vleeskuikens (voeders II en III) en leghennen (begin leg-, midden leg- en eind legvoer). De overzichten zijn bruikbaar als basis voor berekeningen van risicoanalyses van contaminanten in voedermiddelen, voor de berekeningen van effecten van overdracht en vergelijking van normen door de diervoederketen, en als referentiekader voor de toekomstige controle op de open declaratie van diervoeder

Residuen van chlooramfenicol in eieren, lever en mest na intramusculaire toediening bij leghennen

Twaalf leghennen werden geinjecteerd met 75 mg chlooramfenicol per dier. Residu analyse in eieren, lever en mest werd uitgevoerd met behulp van isocratische "reversed phase" HPLC met UV (278-280 nm) detectie

Dissemination of rat cytomegalovirus through infected granulocytes and monocytes in vitro and in vivo

The role of leukocytes in the in vivo dissemination of cytomegalovirus was studied in this experiment. Rat cytomegalovirus (RCMV) could be transferred to rat granulocytes and monocytes by cocultivation with RCMV-infected fibroblasts in vitro. Intravenous injection of purified infected granulocytes or monocytes resulted in a systemic infection in rats, indicating that our model is a powerful tool to gain further insight into CMV dissemination and the development of new antivirals