Hyperoxia increases the uptake of 5-fluorouracil in mammary tumors independently of changes in interstitial fluid pressure and tumor stroma

<p>Abstract</p> <p>Background</p> <p>Hypoxia is associated with increased resistance to chemo- and radiation-therapy. Hyperoxic treatment (hyperbaric oxygen) has previously been shown to potentiate the effect of some forms of chemotherapy, and this has been ascribed to enhanced cytotoxicity or neovascularisation. The aim of this study was to elucidate whether hyperoxia also enhances any actual uptake of 5FU (5-fluorouracil) into the tumor tissue and if this can be explained by changes in the interstitium and extracellular matrix.</p> <p>Methods</p> <p>One group of tumor bearing rats was exposed to repeated hyperbaric oxygen (HBO) treatment (2 bar, pO₂= 2 bar, 4 exposures à 90 min), whereas one group was exposed to one single identical HBO treatment. Animals housed under normal atmosphere (1 bar, pO₂= 0.2 bar) served as controls. Three doses of 5FU were tested for dose response. Uptake of [³H]-5FU in the tumor was assessed, with special reference to factors that might have contributed, such as interstitial fluid pressure (P_if), collagen content, oxygen stress (measured as malondialdehyd levels), lymphatics and transcapillary transport in the tumors.</p> <p>Results</p> <p>The uptake of the cytostatic agent increases immediately after a single HBO treatment (more than 50%), but not 24 hours after the last repeated HBO treatment. Thus, the uptake is most likely related to the transient increase in oxygenation in the tumor tissue. Factors like tumor P_ifand collagen content, which decreased significantly in the tumor interstitium after repeated HBO treatment, was without effect on the drug uptake.</p> <p>Conclusion</p> <p>We showed that hyperoxia increases the uptake of [³H]-5FU in DMBA-induced mammary tumors <it>per se</it>, independently of changes in P_if, oxygen stress, collagen fibril density, or transendothelial transport alone. The mechanism by which such an uptake occur is still not elucidated, but it is clearly stimulated by elevated pO₂.</p

A prospective study of screening for hypertensive disorders of pregnancy at 11-13 weeks in a Scandinavian population

ObjectiveTo investigate the prediction of preeclampsia and gestational hypertension using maternal characteristics, mean arterial pressure (MAP), uterine artery pulsatility index (UtAPI), pregnancy-associated plasma protein-A (PAPP-A) and placental growth factor (PlGF) at gestational weeks 11-13 in a Scandinavian population with a medium to high prior risk for developing hypertensive disorders of pregnancy. DesignProspective screening study. SettingNational Center for Fetal Medicine, Trondheim, Norway. Population579 women who were nulliparous or had a previous history of preeclampsia or gestational hypertension. MethodsWomen were examined between 11(+0) and 13(+6)weeks, with interviews for maternal characteristics and measurements of MAP, UtAPI, PAPP-A and PlGF. The tests were evaluated separately and in combined models with receiver operating characteristics (ROC) curves. Main outcome measuresPrediction of preeclampsia, severe preeclampsia and gestational hypertension. ResultsThe best model for severe preeclampsia (MAP+UtAPI+PlGF+PAPP-A) achieved an area under the ROC curve of 0.866 [95% confidence interval (95% CI) 0.756-0.976]. The best models for preeclampsia (MAP+UtAPI+age) achieved 0.738 (0.634-0.841), gestational hypertension (MAP) 0.820 (0.727-0.913) and hypertensive disorders in pregnancy overall (MAP+PlGF+age) 0.783 (0.709-0.856). Using the best model we could identify 61.5% (95% CI 31.6-86.1) of severe preeclampsia, 38.5% (95% CI 20.2-59.4) of preeclampsia and 42.9% (95% CI 21.8-66) of gestational hypertension at a fixed 10% false-positive rate. ConclusionsMaternal characteristics, MAP, UtAPI, PAPP-A and PlGF showed limited value as screening tests. Further research on biochemical and biophysical tests and algorithms combining these parameters is needed before first trimester screening for hypertensive disorders of pregnancy is included in antenatal care in Scandinavia

Protein expression profiling of plasma and lungs at different stages of metastatic development in a human triple negative breast cancer xenograft model.

The main objective of this study was to identify single proteins or protein networks that might be used as diagnostic biomarkers or for therapeutic purposes by evaluating the protein expression profiling of plasma and lungs at different stages of metastatic development in a human triple negative MDA-MB-231 breast cancer xenograft model. MDA-MB-231 tumour cells were injected into the mammary fat pads on one side of the groin area. The mice were sacrificed day 19 (pre-metastases) and day 54 (metastases). Non-injected mice served as controls. Plasma was collected and lungs harvested for both immunohistochemistry and protein analysis. The most striking observation in plasma was the initial reduction in haptoglobin level at the pre-metastatic stage, to a following significant increase in haptoglobin level at the metastatic stage, with a more than 4000-fold increase from the pre-metastatic to the metastatic phase. A corresponding increase in haptoglobin level was also found in lung tissue after metastasis. Fibrinogen beta chain also had a similar change in expression level in plasma as haptoglobin, however not as prominent. There were also changes in plasma thrombospondin-4 and transferrin receptor protein 1 levels, from an increase at the pre-metastatic stage, to a significant fall when metastases were established. This suggests that especially changes in haptoglobin, but also fibrinogen beta chain, thrombospondin-4 and transferrin receptor protein 1 is indicative of metastasis, at least in this breast cancer model, and should be further evaluated as general breast cancer biomarkers

Stromal integrin α11-deficiency reduces interstitial fluid pressure and perturbs collagen structure in triple-negative breast xenograft tumors

Abstract Background Cancer progression is influenced by a pro-tumorigenic microenvironment. The aberrant tumor stroma with increased collagen deposition, contractile fibroblasts and dysfunctional vessels has a major impact on the interstitial fluid pressure (PIF) in most solid tumors. An increased tumor PIF is a barrier to the transport of interstitial fluid into and within the tumor. Therefore, understanding the mechanisms that regulate pressure homeostasis can lead to new insight into breast tumor progression, invasion and response to therapy. The collagen binding integrin α11β1 is upregulated during myofibroblast differentiation and expressed on fibroblasts in the tumor stroma. As a collagen organizer and a probable link between contractile fibroblasts and the complex collagen network in tumors, integrin α11β1 could be a potential regulator of tumor PIF. Methods We investigated the effect of stromal integrin α11-deficiency on pressure homeostasis, collagen organization and tumor growth using orthotopic and ectopic triple-negative breast cancer xenografts (MDA-MB-231 and MDA-MB-468) in wild type and integrin α11-deficient mice. PIF was measured by the wick-in-needle technique, collagen by Picrosirius Red staining and electron microscopy, and uptake of radioactively labeled 5FU by microdialysis. Further, PIF in heterospheroids composed of MDA-MB-231 cells and wild type or integrin α11-deficient fibroblasts was measured by micropuncture. Results Stromal integrin α11-deficiency decreased PIF in both the orthotopic breast cancer models. A concomitant perturbed collagen structure was seen, with fewer aligned and thinner fibrils. Integrin α11-deficiency also impeded MDA-MB-231 breast tumor growth, but no effect was observed on drug uptake. No effects were seen in the ectopic model. By investigating the isolated effect of integrin α11-positive fibroblasts on MDA-MB-231 cells in vitro, we provide evidence that PIF regulation was mediated by integrin α11-positive fibroblasts. Conclusion We hereby show the importance of integrin α11β1 in pressure homeostasis in triple-negative breast tumors, indicating a new role for integrin α11β1 in the tumor microenvironment. Our data suggest that integrin α11β1 has a pro-tumorigenic effect on triple-negative breast cancer growth in vivo. The significance of the local microenvironment is shown by the different effects of integrin α11β1 in the orthotopic and ectopic models, underlining the importance of choosing an appropriate preclinical model

Stromal integrin α11-deficiency reduces interstitial fluid pressure and perturbs collagen structure in triple-negative breast xenograft tumors

Background: Cancer progression is influenced by a pro-tumorigenic microenvironment. The aberrant tumor stroma with increased collagen deposition, contractile fibroblasts and dysfunctional vessels has a major impact on the interstitial fluid pressure (PIF) in most solid tumors. An increased tumor PIF is a barrier to the transport of interstitial fluid into and within the tumor. Therefore, understanding the mechanisms that regulate pressure homeostasis can lead to new insight into breast tumor progression, invasion and response to therapy. The collagen binding integrin α11β1 is upregulated during myofibroblast differentiation and expressed on fibroblasts in the tumor stroma. As a collagen organizer and a probable link between contractile fibroblasts and the complex collagen network in tumors, integrin α11β1 could be a potential regulator of tumor PIF. Methods: We investigated the effect of stromal integrin α11-deficiency on pressure homeostasis, collagen organization and tumor growth using orthotopic and ectopic triple-negative breast cancer xenografts (MDA-MB-231 and MDA-MB-468) in wild type and integrin α11-deficient mice. PIF was measured by the wick-in-needle technique, collagen by Picrosirius Red staining and electron microscopy, and uptake of radioactively labeled 5FU by microdialysis. Further, PIF in heterospheroids composed of MDA-MB-231 cells and wild type or integrin α11-deficient fibroblasts was measured by micropuncture. Results: Stromal integrin α11-deficiency decreased PIF in both the orthotopic breast cancer models. A concomitant perturbed collagen structure was seen, with fewer aligned and thinner fibrils. Integrin α11-deficiency also impeded MDA-MB-231 breast tumor growth, but no effect was observed on drug uptake. No effects were seen in the ectopic model. By investigating the isolated effect of integrin α11-positive fibroblasts on MDA-MB-231 cells in vitro, we provide evidence that PIF regulation was mediated by integrin α11-positive fibroblasts. Conclusion: We hereby show the importance of integrin α11β1 in pressure homeostasis in triple-negative breast tumors, indicating a new role for integrin α11β1 in the tumor microenvironment. Our data suggest that integrin α11β1 has a pro-tumorigenic effect on triple-negative breast cancer growth in vivo. The significance of the local microenvironment is shown by the different effects of integrin α11β1 in the orthotopic and ectopic models, underlining the importance of choosing an appropriate preclinical model

Evaluating categorization and clinical relevance of drug-related problems in medication reviews

Beskriver en intervensjonsstudie hvor hensikten var å evaluere kategorisering og klinisk relevans av legemiddelrelaterte problem identifisert av kommune-farmasøyter, og vurdere kvaliteten på intervensjoner med pasienter og leger som dokumentert av farmasøyter.Objectives: we aimed to evaluate the categorisation and clinical relevance of DRPs identified by community pharmacists, and further, to assess the quality of interventions with the patients and the physicians as documented by the pharmacists. Setting 23 Norwegian community pharmacies. Method: patients with type 2 diabetes were recruited by 24 community pharmacists who performed structured medication reviews based on the patients’ drug profiles and patient interviews. The DRPs identified were subsequently categorised. An evaluation group (EG) retrospectively evaluated the reviews. Clinical/practical relevance of each DRP and quality of community pharmacists’ intervention with patients and physician were scored. Average agreement between the EG and the community pharmacists was calculated. Internal agreement in the EG was calculated using a modified version of Fleiss’ Kappa coefficient. Results: a total of 73 patients were included (mean age 62 years, 52% female, on average prescribed 8.7 drugs). The pharmacists identified 88 DRPs in 43 of the patients. The most common DRPs were adverse drug reactions (22%) and wrong drug or dose used by patient (14%). Anti-diabetic drugs and lipid modifying drugs were associated with the most DRPs. The EG agreed with detection and categorisation of DRPs in more than 80% of the cases. The clinical/practical relevance of the detected DRPs was scored by the EG to be high or medium in 87% of the cases. The quality of the follow-up with patients and physicians was scored to be good or satisfactory in 93 and 98% of the cases, respectively. Conclusions: pre-defined categories of DRPs supported by structured forms were reliable and valid tools for identifying DRPs. The evaluation demonstrated that community pharmacists were able to identify DRPs of high to medium clinical/practical relevance, and to perform follow-ups of the DRPs with the patients and the physicians with a good or satisfactory quality