O-sulfated bacterial polysaccharides with low anticoagulant activity inhibit metastasis

Heparin-like polysaccharides possess the capacity to inhibit cancer cell proliferation, angiogenesis, heparanase-mediated cancer cell invasion, and cancer cell adhesion to vascular endothelia via adhesion receptors, such as selectins. The clinical applicability of the antitumor effect of such polysaccharides, however, is compromised by their anticoagulant activity. We have compared the potential of chemically O-sulfated and N,O-sulfated bacterial polysaccharide (capsular polysaccharide from E. coli K5 [K5PS]) species to inhibit metastasis of mouse B16-BL6 melanoma cells and human MDA-MB-231 breast cancer cells in two in vivo models. We demonstrate that in both settings, O-sulfated K5PS was a potent inhibitor of metastasis. Reducing the molecular weight of the polysaccharide, however, resulted in lower antimetastatic capacity. Furthermore, we show that O-sulfated K5PS efficiently inhibited the invasion of B16-BL6 cells through Matrigel and also inhibited the in vitro activity of heparanase. Moreover, treatment with O-sulfated K5PS lowered the ability of B16-BL6 cells to adhere to endothelial cells, intercellular adhesion molecule-1, and P-selectin, but not to E-selectin. Importantly, O-sulfated K5PSs were largely devoid of anticoagulant activity. These findings indicate that O-sulfated K5PS polysaccharide should be considered as a potential antimetastatic agent.</p

Radiosynthesis and preclinical evaluation of [68Ga]Ga-NOTA-folate for PET imaging of folate receptor β-positive macrophages

Folate receptor β (FR-β), a marker expressed on macrophages, is a promising target for imaging of inflammation. Here, we report the radiosynthesis and preclinical evaluation of [68Ga]Ga-NOTA-folate (68Ga-FOL). After determining the affinity of 68Ga-FOL using cells expressing FR-β, we studied atherosclerotic mice with 68Ga-FOL and 18F-FDG PET/CT. In addition, we studied tracer distribution and co-localization with macrophages in aorta cryosections using autoradiography, histology, and immunostaining. The specificity of 68Ga-FOL was assessed in a blocking study with folate glucosamine. As a final step, human radiation doses were extrapolated from rat PET data. We were able to produce 68Ga-FOL with high radiochemical purity and moderate molar activity. Cell binding studies revealed that 68Ga-FOL had 5.1 nM affinity for FR-β. Myocardial uptake of 68Ga-FOL was 20-fold lower than that of 18F-FDG. Autoradiography and immunohistochemistry of the aorta revealed that 68Ga-FOL radioactivity co-localized with Mac-3–positive macrophage-rich atherosclerotic plaques. The plaque-to-healthy vessel wall ratio of 68Ga-FOL was significantly higher than that of 18F-FDG. Blocking studies verified that 68Ga-FOL was specific for FR. Based on estimations from rat data, the human effective dose was 0.0105 mSv/MBq. Together, these findings show that 68Ga-FOL represents a promising new FR-β–targeted tracer for imaging macrophage-associated inflammation.</p

Rediscovering vitamin D

Over the past 2 years there has been a radical change in standard clinical practice with respect to vitamin D. As a result of a growing body of knowledgeable physicians are assessing the vitamin D nutritional status of their patients and prescribing aggressive repletion regimens of a vitamin D supplement. The present paper summarizes some basic information about this essential nutrient and reviews some of the more recent data implicating vitamin D deficiency in disease etiology with an emphasis on cardiovascular disease and cancer. Finally a rational approach to the dosing of vitamin D in different patient populations is provided

Fast growth associated with aberrant vasculature and hypoxia in fibroblast growth factor 8b (FGF8b) over-expressing PC-3 prostate tumour xenografts

Background: Prostate tumours are commonly poorly oxygenated which is associated with tumour progression and development of resistance to chemotherapeutic drugs and radiotherapy. Fibroblast growth factor 8b (FGF8b) is a mitogenic and angiogenic factor, which is expressed at an increased level in human prostate tumours and is associated with a poor prognosis. We studied the effect of FGF8b on tumour oxygenation and growth parameters in xenografts in comparison with vascular endothelial growth factor (VEGF)-expressing xenografts, representing another fast growing and angiogenic tumour model. Methods: Subcutaneous tumours of PC-3 cells transfected with FGF8b, VEGF or empty (mock) vectors were produced and studied for vascularity, cell proliferation, glucose metabolism and oxygenation. Tumours were evaluated by immunohistochemistry (IHC), flow cytometry, use of radiolabelled markers of energy metabolism ([F-18] FDG) and hypoxia ([F-18] EF5), and intratumoral polarographic measurements of pO(2). Results: Both FGF8b and VEGF tumours grew rapidly in nude mice and showed highly vascularised morphology. Perfusion studies, pO(2) measurements, [F-18] EF5 and [F-18] FDG uptake as well as IHC staining for glucose transport protein (GLUT1) and hypoxia inducible factor (HIF) 1 showed that VEGF xenografts were well-perfused and oxygenised, as expected, whereas FGF8b tumours were as hypoxic as mock tumours. These results suggest that FGF8b-induced tumour capillaries are defective. Nevertheless, the growth rate of hypoxic FGF8b tumours was highly increased, as that of well-oxygenised VEGF tumours, when compared with hypoxic mock tumour controls. Conclusion: FGF8b is able to induce fast growth in strongly hypoxic tumour microenvironment whereas VEGF-stimulated growth advantage is associated with improved perfusion and oxygenation of prostate tumour xenografts

Root growth dynamics in golf greens with different compression intensities and winter survival

The aim of this study was to measure root growth dynamics under Nordic putting green conditions in order to estimate the sensitivity of root growth to winter damages and compression. Root numbers of turfgrasses were measured from soil depths of 040 cm by minirhizotrons. The minirhizotrons tubes were installed in the most compressed (center) and less walked (edge) parts of putting greens with good or weak winter survival. The highest root numbers were recorded under less walked green edge areas with good winter survival. The lowest root numbers were measured from center areas of greens, especially from areas suffering winter damage in previous years. Morphological parameters of roots were studied by a destructive soil sampling method in midseason 1998. Based on image analysis of washed roots, root length density at soil depths of 02.5 cm was 400 cm cm3 in greens of weak winter survival and up to 900 cm cm3 in greens of good winter survival. Our findings emphasize that root growth of turfgrasses is highly dynamic and sensitive to compression despite of non significant effects on soil porosity. Reduced root growth of greens with weak winter survival continued despite of recovery of shoot growth.;Maan tiivistyminen vaikeuttaa juuriston kasvua sekäedelleen kasvien veden ja ravinteiden ottoa. Golfviheriöillä pelaamisesta aiheutuvan tallauksen tiedetään vahingoittavan kasvustoa, mutta tallauksen vaikutuksista juuristoon on vähän tietoa. Varsinkin huonosti talvehtineilla viheriöillä kasvuston on todettu olevan erityisen arka pelaamisesta aiheutuvalle kulutukselle. Tämän tutkimuksen tavoitteena oli mitata pelaamisesta aiheutuvan tallauksen vaikutuksia viheriöiden nurmikkoheinien juuriston kasvuun kasvukauden eri aikoina. Juuriston kasvua mitattiin sekä hyvin että heikosti talvehtineilla viheriöillä. Tutkimus toteutettiin 19971999 Hyvinkäällä Hyvigolfin kentällä, jonka viheriöillä kasvoi kylänurmikkaa ja rönsyrölliä. Tutkimusmenetelminä käytettiin miniritsotronitekniikkaa ja maasta erikseen pestyjen juurien kuva-analyysiä. Miniritsotronit eli läpinäkyvät muoviputket (halkaisija 5 cm, pituus 60 cm) sijoitettiin syksyllä 1997 viheriöiden laidoille ja keskiosiin 45 asteen kulmaan maanpintaan nähden. Seuraavina vuosina juurikuvia tallennettiin putkien sisältä videokameralla 040 cm:n syvyyksissä. Juurikuvat (2,43 cm2) tallennettiin putkien yläpinnasta, ja kuvaus kohdennettiin samoihin kuva-alueisiin jokaisella 14 mittauskerralla. Kesällä 1998 otettiin lisäksi maanäytteitä, joista juuret eroteltiin vesi- ja ilmavirran avulla hydropneumaattisella elutrointi-laitteella. Juuret värjättiin ja skannattiin vesipatjan päällä lasitarjottimella. Skannatusta digitaalisesta kuva-aineistosta määritettiin juurien pituus ja paksuus kuva-analyysin avulla. Tulosten mukaan viheriöiden nurmikkoheinien juurten määrä vaihteli suuresti kasvukauden eri aikoina. Keväällä juuriston kasvu oli nopeaa, mutta videokuvista lasketut juurien ja juurten haarojen lukumäärät tasaantuivat keskikesällä. Tallatuilla viheriöiden keskiosilla juuria havaittiin huomattavasti vähemmän kuin viheriöiden reunoilla. Hyvin talvehtineilla ja vähän tallatuilla viheriöiden osilla juurien lukumäärät olivat suurimmat. Suurin osa juuristosta kasvoi 05 cm:n kerroksessa. Kuva-analyysin perusteella juuritiheys (= pituus maatilavuudessa) oli 20 cm:n syvyydessä keskimäärin 180 cm/cm3 hyvin talvehtineilla ja 110 cm/cm3 huonosti talvehtineilla viheriöillä (n = 4). Maan pinnassa (02,5 cm) vastaavat juuritiheydet olivat jopa 900 ja 400 cm/cm3, joka vastaa ulkomailla mitattuja golfnurmikkoheinien tiheyksiä. Tallausvaikutus oli suurin pintamaassa. Penetrometrillä mitattu maan mekaaninen vastus tai huokostilavuus ei kuitenkaan muuttunut merkittävästi 010 cm: n syvyydessä. Tulos viittaa siihen, että tallaus vaikutti juuristoon kuluttamalla maan päällistä kasvustoa, painamalla kuitukerrosta kasaan ja tuhoamalla maan huokosten jatkuvuutta. Kuitukerroksen painuminen kasaan hidastaa kaasujen vaihtoa, ja huokosten jatkuvuuden tuhoutuminen hidastaa veden johtavuutta kasvualustassa. Nämä muutokset saattavat aiheuttaa talvivaurioita lisäämällä jään muodostusta. Tutkimuksen mukaan huonosti talvehtineilla viheriöillä juuriston kasvu oli heikentynyt vielä kaksi vuotta talvivaurioiden toteamisen jälkeen, vaikka maanpäällinen kasvusto oli jo elpynyt