Genetic interaction analysis of VEGF-A rs3025039 and VEGFR-2 rs2071559 identifies a genetic profile at higher risk to develop nodular goiter.

CONTEXT: Nodular goiter in patients from areas of iodine deficiency is due to the growth of follicular and endothelial cells, involving different vascular-related growth factors in its pathogenesis. OBJECTIVE: The aim of our study was to examine the association of known single polymorphisms of vascular endothelial growth factor-A [VEGF-A], VEGF receptor-2 [VEGFR-2] and hypoxia-inducible factor-1α [HIF-1α] genes or their genetic interactions with the risk of nodular goiter development. PATIENTS AND METHODS: 116 normal subjects, without any thyroid disease, and 108 subjects with nodular goiter [subjects with goiter and at least one thyroid nodule of > 1 cm of maximum size and in absence of signs of autoimmunity] were selected from a homogeneous population living in a mild iodine deficiency geographic area. Analyses were performed on germline DNA obtained from blood samples and VEGF-A rs3025039, VEGFR-2 rs2071559, and HIF-1αrs11549465 SNPs were investigated by real-time PCR technique. The multifactor dimensionality reduction [MDR] methodology was applied to investigate the genetic interaction between SNPs. Hardy-Weinberg equilibrium was performed. RESULTS: None of the studied polymorphisms were individually associated with a higher risk to develop nodular goiter [P > 0.05]. The combination of the VEGF-A rs3025039 and VEGFR-2 rs2071559 polymorphisms had the highest accuracy of 0.58 [P = 0.018] and the interaction of some genotypes was significantly associated with the risk of nodular goiter development. CONCLUSIONS: Our results support a genetic interaction between the VEGF-A rs3025039 and VEGFR-2 rs2071559 polymorphisms as a predictor of the risk to develop nodular goiter in subjects coming from an area with mild iodine deficiency.

Generous breastfeeding: an observational retrospective study of milk donor's characteristics in the province of Siena, Italy.

BACKGROUND: Breastfeeding is definitely one of the measures capable of improving not only children's but also mother's health. Human milk banks are institutions providing human milk to babies with limited access to breastfeeding for various reasons. STUDY DESIGN: The aim of this observational retrospective study was to examine principal characteristics of breast milk donors in the province of Siena and to identify variables influencing Milk Quantity (MQ) and Length of donation period (LD). METHODS: Information was extracted from medical records of Human Milk Bank of Siena, all women that donated their breast milk during the period from January 2010 until August 2017 were included. Examined variables were: age, place of birth (Italy/outside Italy), residence (Siena city/Siena province), education, profession, type of labor (preterm/in-term) and type of delivery (vaginal/cesarean section), gestational age, number of children, previous donations (blood, milk), quantity of donated milk and length of donation. RESULTS: A total of 304 donors were included: 75.7% of Italian nationality. The mean age was 32.4±5.2, Italian donors were older (33.5±5.0 vs. 28.7±4.2; Mann-Whitney; p<0.001). Socio-economic situation of Italian donors was better compared to non-Italian donors (chi-squared; p<0.005). Non-Italian donors had more probability to go through preterm labor (OR=3.68; p<0.001). Average length of donation was 2.7±1.8 months. Mean quantity of donated milk was 4.8±7.6l. From multiple linear regression, preterm birth (p<0.005) and length of donation (p<0.001) emerged as a variable that can predict higher quantity of donated milk. CONCLUSIONS: Preterm babies are usually recovering in a neonatology intensive therapy unit, with mothers staying close to them, which facilitates the whole donation process. Mothers of premature babies have a higher perception of the meaningfulness of donation and a need of adequate nutrition for fragile infants.

Midwives in England and in Italy: two realities compared.

BACKGROUND: Midwives have the responsibility to provide assistance to pregnant women for non-complicated deliveries. The aim of this study was to identify the distinctive features of midwives in Italy and in England in order to provide interesting comparisons. METHODS: From September to October 2015 we administered an online questionnaire to groups of Italian and English midwives. The questionnaire was composed by a part trying to collect the sociodemographic information and a second part to define the attitudes of care and the type of approach to birth and degree of attained professional autonomy. The questions were used to create a score for 5 macro areas: "Midwifery: who is the midwife?", "Education: how much does the midwife know?", "Responsibility: what does the midwife do?", "Ethics: how does the midwife act?", "Social acknowledgment: the midwife and the other people". Results were loaded in a database and analyzed using the using STATA. RESULTS: 183 Midwives (100 Italian and 83 English) completed the questionnaire. 92% of Italian respondents said to have a "Bachelor", 6% a "University Diploma" and only 2% a "Diploma". 80% of British midwives had a "Midwifery Degree" and 8% attended a "Midwifery Short Program", a degree course in Nursing with an additional specialization of a year and a half in Midwifery. 34% of the Italian claimed to have also a "1st level Master", 16% a "Full Degree" and the remaining 50% attended post degree training courses. Only 23% of the English sample had a "Master of Science" and the remaining 67% reported to have "other" general qualifications. 72% of Italian midwives declared to work and, in particular, in a "III level point of birth" (35%), "II level point of birth" (25%), "I level point of birth" (17%), or in "private health facilities" (4%), in "professional offices" (6%) or "counseling ambulatories" (5%). 46% of the English midwives who participated in the study worked in hospitals; 21% as employees of the NHS in territorial structures. 12% worked in birth centers and 11% had a private profession. There was a statistically significant difference between Italian and English Midwives, for all the macro areas (except for the first), with better results for English Midwives. CONCLUSION: English Midwives tend to consider their professional role and their professional skills more acknowledged and appreciated than Italian Midwives. Actually Italians tend to be not very satisfied. However, the Midwives of both countries feel very close to women and have the same conception of themselves and of their profession.

Factors that could influence women's participation in colorectal cancer screening: an Italian study.

BACKGROUND: Colorectal cancer (CRC) is the 2nd most common cancer in women worldwide. In Italy, only 50% of people invited to get the Fecal Occult Blood Test (FOBT) decided to do it. Women's participation in breast and cervical screening is, instead, very high (>70%). The aim of our study was to investigate the beliefs, the feelings and the psychological factors that could influence the participation of women in CRC screening. METHODS: We conducted a cross sectional study, in the Hospital of Siena, Central Italy, in 2011. We administered a questionnaire to 507 women of all ages, who attended mammography or clinical breast examination. The adherence to CRC screening was analyzed only in the group of 207 older women (age >50 years). We performed descriptive, bivariate and logistic regression analysis to identify whether an association was present between participant characteristics, willingness and adherence to screening. RESULTS: Family history of colorectal cancer (OR 4.3; p<0.007) and the General Practitioner's advice (OR: 3.4; p<0.003) were associated with a greater adherence to screening (colonoscopy). The embarrassment was another factor related to colonoscopy compliance (OR: 0.34; p<0.016). CONCLUSION: Family history of CRC, pain or embarassment and GP's advice are the factors that correlated more strongly (positively or negatively) with adherence to colorectal cancer screening. These elements should be further analyzed to choose the best solution to improve the adherence in campaigns on colorectal cancer.

Health status of homeless persons: a pilot study in the Padua municipal dorm.

OBJECTIVES: Homeless persons can be considered a vulnerable group and several studies showed in this group an higher prevalence of chronic and infectious diseases, a lower mental health status, and a higher abuse of alcohol. The aim of our study was to investigate the health status of homeless in Padua, Italy, administering a questionnaire composed by SF-36 and EQ-5D. DESIGN: We conducted a cross-sectional study from 15 December 2015 to 15 February 2016. SETTING AND PARTICIPANTS: We enrolled in our study 73 homeless persons welcomed in the municipal dorm of Padua. 5 persons refused to participate in the study; 9 had a mental status incompatible with the participation to the study. MAIN OUTCOME MEASURES: We administered to the participants a questionnaire composed by three parts: in the first part we asked sociodemographic information (gender, age, nationality, qualification, height and weight) to calculate BMI, time spent at the dorm, period of homelessness, alcohol intake, smoking habit, availability of a general practitioner, emergency room visits in the last year, admissions in the last year, pre-existing conditions and in act, participation in screening programs. The second part was represented by the Short Form 36 questionnaire. The third part by the EQ-5D questionnaire. RESULTS: Our sample was composed by 79% men and 21% women. 54.7% were Italian. The mean age was 48 years. 72.8% were smoker and 60,3% drunk alcohol. In this latter group 28.8% drunk more than 1 liter of wine per day. Non Italian homeless smoke less than the Italian: this difference is statistically significant (OR = 3.7 p = 0.032 ). Only 9 foreigners had a general practitioner compared to 30 Italian homeless: this difference is statistically significant (OR = 60 P < 0.01). 43 of the 59 respondents (72.8 % ) said to suffer from some disease. No one reported a history of tuberculosis. The most represented diseases were pneumonia (30%), myocardial infarction (17%), hepatitis C (13.5%). Participation in screening programs was very low. From the analysis of the SF-36 results, homeless persons obtained lower scores than Italian population. In our study, 40 persons reported a level 2 or 3 in the EQ-5D dimension called "anxiety/ depression". In the EQ visual-analogue scale, the homeless population showed a lower perception of its health status. CONCLUSION: Compared to the general population, the homeless reported a worse mental health, and this showed that they represent a particularly vulnerable group. Moreover they had a higher percentage of incorrect habits for their health (alcoholism and tobacco addiction), they suffered from chronic conditions, and tended to have a higher frequency of accesses to the emergency rooms. It would be better to improve the state of health of the homeless, through initiatives that could reduce the causes of homelessness, and that could prevent the onset of diseases in this group.

The c.480C>G polymorphism of hOCT1 influences imatinib clearance in patients affected by chronic myeloid leukemia.

The aim of the study was to investigate any possible influence of polymorphisms of transmembrane transporters human organic cation transporter 1 (hOCT1), ABCB1, ABCG2 on imatinib pharmacokinetics in 33 men and 27 women (median age and range, 56 and 27-79 years, respectively) affected by chronic myeloid leukemia. A population pharmacokinetic analysis was performed to investigate imatinib disposition in every patient and the role of transporter polymorphisms. Results showed that the α1-acid glycoprotein and the c.480C>G genotype of hOCT1 had a significant effect on apparent drug clearance (CL/F) being responsible, respectively, for a 20% and 10% decrease in interindividual variability (IIV) of CL/F (from 50.1 up to 19.6%). Interestingly, 25 patients carrying at least one polymorphic c.480 G allele had a significant lower CL/F value with respect to the 35 c.480CC individuals (mean±s.d., 9.6±1.6 vs 12.1±2.3 l h(-1), respectively; P<0.001). In conclusion, the hOCT1 c.480C>G SNP may significantly influence imatinib pharmacokinetics, supporting further analyses in larger groups of patients.

VEGF-A polymorphisms predict progression-free survival among advanced castration-resistant prostate cancer patients treated with metronomic cyclophosphamide.

BACKGROUND: No data are available on the pharmacogenetics of metronomic chemotherapy in prostate cancer. The aim of this study was to evaluate the association between VEGF-A sequence variants and prostate-specific antigen (PSA) progression, progression-free survival (PFS) and overall survival (OS), in advanced castration-resistant prostate cancer patients treated with metronomic cyclophosphamide (CTX), celecoxib and dexamethasone. METHODS: Forty-three patients were enrolled, and genomic DNA was extracted. VEGF-A gene SNPs (-2578A/C, -634C/G, +936C/T) were analysed using TaqMan PCR assays. Hardy-Weinberg equilibrium was tested for each SNP, and genetic effects were evaluated by Fisher's exact test. PFS and OS were analysed with GraphPad Prism software, using the product limit method of Kaplan and Meier, and comparing survival curves using both the log-rank test and the Gehan-Wilcoxon test. We used Bonferroni correction to account for multiple testing, and a two-tailed P-value of <0.017 was considered statistically significant. RESULTS: Overall, 20 patients (46%) experienced a reduction in PSA levels from baseline and, among them, 14 (32%) showed a confirmed PSA ≥50% decrease. In non-responders, the -2578CC genotype was more frequent (18.60% vs 2.33% in responders; P=0.0212) whereas the -634CC genotype frequency was 22.73% vs 0% in responders (P=0.0485). With regard to PFS, patients harbouring the -634CC genotype had a median PFS of 2.2 months whereas patients with the genotype -634CG/GG had a median PFS of 6.25 months (P=0.0042). CONCLUSION: The -634CC genotype is significantly associated with a shorter PFS in patients treated with a metronomic CTX schedule.

Aurora B kinase inhibitor AZD1152: determinants of action and ability to enhance chemotherapeutics effectiveness in pancreatic and colon cancer.

BACKGROUND: AZD1152, the prodrug for AZD1152-hydroxyquinazoline pyrazol anilide (HQPA), is a selective inhibitor of Aurora B kinase activity. Preclinical evaluation of AZD1152 has been reported in several human cancer models. The potentiality of this compound in combination therapy warrants further investigation in solid tumours. EXPERIMENTAL DESIGN: This study explored the effects of AZD1152-HQPA in colon and pancreatic tumour cells. The antitumour properties of AZD1152, either as single agent or in combination with chemotherapeutics, were evaluated in each study model. The efficacy and the toxicity of AZD1152 alone and in combination with gemcitabine were validated in pancreatic tumour xenograft model. RESULTS: AZD1152-HQPA treatment resulted in a dramatic increase of chromosome number, modification of cell cycle and induction of apoptosis. The most effective combination was that with chemotherapeutics given soon after AZD1152 in both tumour cell types. The effectiveness of the sequential schedule of AZD1152 with gemcitabine was confirmed in nude mice bearing MiaPaCa-2 tumours, showing inhibition of tumour volumes and delaying of tumour growth after the interruption of the treatments. Here we show that AZD1152-HQPA enhances oxaliplatin and gemcitabine effectiveness in colon and pancreatic cancer, respectively. First, we provide advances into administration schedules and dosing regimens for the combination treatment in in vivo pancreatic tumour.

Pharmacodynamic and pharmacogenetic angiogenesis-related markers of first-line FOLFOXIRI plus bevacizumab schedule in metastatic colorectal cancer.

BACKGROUND: The identification of molecular and genetic markers to predict or monitor the efficacy of bevacizumab (BV) represents a key issue in the treatment of metastatic colorectal cancer (mCRC). METHODS: Plasma levels of vascular endothelial growth factor (VEGF), placental growth factor (PlGF), soluble VEGF receptor 2 (sVEGFR-2) and thrombospondin-1 (TSP-1) were assessed by ELISA assay at different time points in a cohort of 25 patients enroled in a phase II trial of GONO-FOLFOXIRI plus BV as first-line treatment of mCRC. VEGF: -2578A/C, -1498C/T, -1154A/G, -634C/G and 936C/T; and VEGFR-2: -604A/G, +1192C/T and +1719A/T, polymorphisms were assessed in a total of 54 patients. RESULTS: Treatment with GONO-FOLFOXIRI plus BV determined a prolonged and significant reduction in plasma free, biologically active VEGF concentration. Interestingly, VEGF concentrations remained lower than at baseline also at the time of PD. Conversely, PlGF levels increased during the treatment if compared with baseline, suggesting a possible role in tumour resistance; moreover, sVEGFR-2 increased at the time of PD, as well as TSP-1. No association of assessed polymorphisms with outcome was found. CONCLUSION: Our study suggested the possible mechanisms of resistance to combined therapy in those patients with a progressive disease to be tested in ongoing phase III randomised studies.

Antiangiogenic and anticolorectal cancer effects of metronomic irinotecan chemotherapy alone and in combination with semaxinib.

Metronomic chemotherapy refers to the administration of chemotherapy at low, nontoxic doses on a frequent schedule with no prolonged breaks. The aim of the study is to rationally develop a CPT-11 metronomic regimen in preclinical settings of colon cancer. In vitro cell proliferation, apoptosis and thrombospondin-1/vascular endothelial growth factor (TSP-1/VEGF) expression analyses were performed on endothelial (HUVEC, HMVEC-d) and colorectal cancer (HT-29, SW620) cells exposed for 144 h to metronomic concentrations of SN-38, the active metabolite of CPT-11. HT-29 human colorectal cancer xenograft model was used, and tumour growth, microvessel density and VEGF/TSP-1 quantification was performed in tumours. In vitro and in vivo combination studies with the tyrosine inhibitor semaxinib were also performed. SN-38 preferentially inhibited endothelial cell proliferation alone and interacted synergistically with semaxinib; it induced apoptosis and increased the expression and secretion of TSP-1. Metronomic CPT-11 alone and combined with semaxinib significantly inhibits tumour growth in the absence of toxicity, which was accompanied by decreases in microvessel density and increases in TSP-1 gene expression in tumour tissues. In vitro results show the antiangiogenic properties of low-concentration SN-38, suggesting a key role of TSP-1 in this effect. In vivo, the CPT-11 metronomic schedule is effective against tumour and microvessel growth without toxic effect on mice.

A pharmacokinetic and pharmacodynamic study on metronomic irinotecan in metastatic colorectal cancer patients.

The pharmacokinetics (PK) and pharmacodynamics (PD) of metronomic irinotecan have not been studied in cancer patients. The aim of the study is to investigate the PK/PD profile of irinotecan/SN-38 administered by metronomic schedule. Twenty chemotherapy-refractory or chemotherapy-resistant patients with metastatic colorectal carcinoma were enrolled. Irinotecan was infused continuously as follows: irinotecan 1.4 mg m(-2) day(-1) (n=7), 2.8 mg m(-2) day(-1) (n=5) and 4.2 mg m(-2) day(-1) (n=8). Drug levels were examined by HPLC, whereas ELISAs and real-time RT-PCR were used, respectively, for the measurement of plasma levels and gene expression in peripheral blood mononuclear cells of vascular endothelial growth factor/thrombospondin-1. Pharmacokinetic analysis demonstrated that the steady-state levels (C(ss)) of SN-38 were between 1 and 3.3 ng ml(-1). From a PD point of view, higher thrombospondin-1 (TSP-1) plasma levels (153.4+/-30.1 and 130.4+/-9.2% at day 49 vs pretreatment values at 1.4 and 2.8 mg m(-2) day(-1) dose levels, respectively) and increased gene expression in PBMC were found during the metronomic irinotecan infusion, especially at the lower doses. Four patients (20%) obtained a stable disease (median 3.9 months) despite progressing during previous standard irinotecan schedule. Toxicities >grade 1 were not observed. Metronomic irinotecan administration is very well tolerated and induces an increase of gene expression and plasma concentration of TSP-1 at low plasma SN-38 concentrations.

Modelling the aquatic toxicity of ionic liquids by means of VolSurf in silico descriptors.

VolSurf+ in silico physicochemical descriptors for both the cationic and the anionic counterparts of ionic liquids (ILs) have been derived. These descriptors, suitable for molecular modelling of IL structures which, due to their amphiphilic nature, interact strongly with biological matrices, can be related to aquatic toxicity by means of a partial least squares statistical model. This model gives an insight into the relationships between structural physicochemical properties and aquatic toxicity as well as a satisfactory quantitative structure-property correlation, allowing prediction of aquatic toxicity scores of ILs.

Cyto- and enzyme toxicities of ionic liquids modelled on the basis of VolSurf+ descriptors and their principal properties.

Five in silico principal properties (PPs) for 218 heterocyclic cations and four PPs for 38 organic and inorganic anionic counterparts of ionic liquids (ILs) were derived by the VolSurf+ approach. VolSurf+ physicochemical descriptors take into account several cationic structural features of ILs such as heterocyclic aromatic and non-aromatic cationic cores, alkyl chain length, presence of oxygen atoms in the substituents as well as the properties of a wide variety of inorganic and organic anions. Combination of these cation and anion PPs can provide descriptors for over 8000 ILs, thus allowing the development of QSPR models for IL cytotoxicity (IPC-81 rat cell line) and enzyme toxicity (acetylcholinesterase inhibition). The adoption of a Partial Least Squares approach, relating PPs and toxicities, provided affordable predictions for ILs in both learning and external validation sets, implying the possibility to extend the predictive model to a set of 520 ILs. This allows us to establish priorities in selecting ILs for experimental hazard assessment as required by the REACH regulation.

Comparative pharmacokinetic analysis of 5-fluorouracil and its major metabolite 5-fluoro-5,6-dihydrouracil after conventional and reduced test dose in cancer patients.

The aim of this study was to investigate the clinical pharmacokinetics of 5-fluorouracil (5-FU) and its major metabolite 5-fluoro-5,6-dihydrouracil (5-FDHU) in 20 colorectal cancer patients given two dose levels of 5-FU, 250 and 370 mg/m2, administered by i.v. bolus. A reverse-phase high-performance liquid chromatographic method was used for the simultaneous assay of 5-FU and 5-FDHU in plasma samples obtained at baseline and at multiple time points from 5 min to 4 h after 5-FU bolus as well as to assess the activity of dihydropyrimidine dehydrogenase (DPD) in peripheral blood mononuclear cells (PBMCs) before 5-FU dosing. Plasma pharmacokinetic parameters of patients given 250 mg/m2 5-FU were significantly different from those receiving 370 mg/m2; main differences were observed in the trapezoidal areas under the plasma levels-versus-time curve from to to the last measurable concentration (area under the curve, 3.77+/-0.21 versus 13.61+/-2.3 h x microg/ml), peak plasma concentration (Cmax, 18.15+/-1.35 versus 48.41+/-7.69 microg/ml), and total body clearance (CL(TB), 54.64+/-3.54 versus 25.43+/-2.3 l/h/m2). Significant differences were also observed in the main pharmacokinetic parameters of 5-FDHU after 250 and 370 mg/m2 5-FU including the area under the curve from to to 4 h (5.39+/-0.32 versus 8.75+/-1.24 h x microg/ml), Cmax (3.60+/-0.16 versus 5.26+/-0.55 microg/ml) and time to Cmax (Tmax, 0.45+/-0.03 versus 0.69+/-0.06 h). The mean DPD activity in PBMCs in this group of patients was 205.7+/-36.4 pmol of 5-FDHU/min/mg of protein and was within the normal range; however, no significant correlations were found between 5-FU or 5-FDHU pharmacokinetic parameters at two dose levels and DPD activity of PBMCs. The results of the present study provide the first detailed comparison of the distribution of 5-FU and its major metabolite 5-FDHU at the therapeutic level as well as at reduced test dose levels to obtain pharmacokinetic data to be used as reference values for the identification of patients at risk of major 5-FU toxicity due to impaired metabolism to 5-FDHU.

Inhibition of experimental angiogenesis by the somatostatin analogue octreotide acetate (SMS 201-995).

The present study investigates the effect of the somatostatin analogue octreotide acetate (SMS 201-995) on experimental angiogenesis in vitro and in vivo. Octreotide reduced the proliferation of human HUV-EC-C endothelial cells (mean, -45.8% versus controls at 10(-9) M; P < 0.05) as well as the density of the vascular network of the chick chorioallantoic membrane (mean, -35.7% versus controls at 50 microgram; P < 0.05). Furthermore, octreotide significantly inhibited chick chorioallantoic membrane neovascularization by the human MCF-10Aint-2 mammary cells secreting the angiogenic protein FGF-3. The proliferation of endothelial and smooth muscle cells from rat aorta explants on fibronectin was reduced by octreotide 10(-8) M (mean, -32.6% versus controls; P < 0.05), and a similar effect was produced on cells sprouting from explants cultured in fibrin (mean, -52.9% versus controls; P < 0.05). Topical administration of octreotide 10 microgram/day for 6 days inhibited rat cornea neovascularization induced by AgNO3/KNO3 (mean, -50.6% versus controls; P < 0.05). Octreotide 40 microgram/day i.p was tested on angiogenesis in rat mesentery obtained by i.p. injections of compound 48/80, a mast cell degranulating agent, or conditioned medium from MCF-10Aint-2 cells and was able to reduce the extent of neovascularization (mean, -45.6 and -64.1%, respectively, versus controls; P < 0.05). These data provide evidence that octreotide is an inhibitor of experimental angiogenesis in vitro and in vivo.

Idarubicin and idarubicinol effects on breast cancer multicellular spheroids.

Despite extensive preclinical evaluation in several experimental models, no studies have determined the effect of idarubicin and its metabolite idarubicinol on multicellular spheroids, a model which mimics the microregions of solid tumors. The principal aim of the present study was to investigate the in vitro cytotoxicity of idarubicin and its metabolite idarubicinol on MCF-7 breast cancer cells growing as monolayers or multicellular spheroids and to evaluate the influence of the length of exposure on the cytotoxic effect of both drugs. Cytoxicity was evaluated on monolayer and spheroid cultures exposed to idarubicin and idarubicinol 0.01-1000 ng/ml for 24 h or treated for 6, 12, 24 and 48 h to 100 ng/ml of both drugs. The IC50 of idarubicin and idarubicinol were 3.3+/-0.4 and 3.6+/-0.7 ng/ml, respectively, on MCF-7 monolayers and 7.9+/-1.1 and 5.3+/-0.7 ng/ml in multicellular spheroids, respectively. The antiproliferative effects of 100 ng/ml idarubicin and idarubicinol on MCF-7 spheroids was characterized by a marked time-dependence, which was less evident on MCF-7 growing as monolayer. In conclusion, the present experimental data demonstrate, for the first time, that idarubicin and idarubicinol have significant cytotoxic activity against multicellular spheroids, comparable to the antiproliferative effects on monolayer cells. In contrast, spheroids displayed substantial resistance after short exposure times that was not present in the two dimensional cultures.

Combining a weed traits database with a population dynamics model predicts shifts in weed communities.

A functional approach to predicting shifts in weed floras in response to management or environmental change requires the combination of data on weed traits with analytical frameworks that capture the filtering effect of selection pressures on traits. A weed traits database (WTDB) was designed, populated and analysed, initially using data for 19 common European weeds, to begin to consolidate trait data in a single repository. The initial choice of traits was driven by the requirements of empirical models of weed population dynamics to identify correlations between traits and model parameters. These relationships were used to build a generic model, operating at the level of functional traits, to simulate the impact of increasing herbicide and fertiliser use on virtual weeds along gradients of seed weight and maximum height. The model generated 'fitness contours' (defined as population growth rates) within this trait space in different scenarios, onto which two sets of weed species, defined as common or declining in the UK, were mapped. The effect of increasing inputs on the weed flora was successfully simulated; 77% of common species were predicted to have stable or increasing populations under high fertiliser and herbicide use, in contrast with only 29% of the species that have declined. Future development of the WTDB will aim to increase the number of species covered, incorporate a wider range of traits and analyse intraspecific variability under contrasting management and environments.

Inhibitory effect of suramin in rat models of angiogenesis in vitro and in vivo.

The aim of the present study was to test the ability of the chemotherapeutic agent suramin to inhibit angiogenesis in experimental models in vitro and in vivo. In the culture of rat aortic rings on fibronectin, suramin dose-dependently inhibited vascular cell growth, achieving the maximal effect (mean - 88% versus controls, P < 0.05) at 400 microg/ml. Image analysis showed that suramin could inhibit microvessel sprouting in fibrin from rat aortic rings as evaluated by the ratio between the cellular area and the mean gray value of the sample (sprouting index); suramin at 50 microg/ml significantly reduced the sprouting index from the control value of 0.35+/-0.04 to 0.14+/-0.02 mm2/gray level (P < 0.05). Likewise, the area occupied by cells was 19.2+/-1.8 mm2 as compared with 41.8+/-4.2 mm2 in controls (P < 0.05). In the rat model of neovascularization induced in the cornea by chemical injury, suramin at 1.6 mg/eye per day reduced the length of blood vessels (0.7+/-0.1 mm as compared with 1.5+/-0.1 mm in controls, P < 0.05). In the same model the ratio between the area of blood vessels and the total area of the cornea (area fraction score) was decreased by suramin from 0.19+/-0.02 in controls to 0.03+/-0.003 (P < 0.05). Suramin given i.p. at 30 mg/ kg per day markedly inhibited the neovascularization induced in the rat mesentery by compound 48/80 or conditioned medium from cells secreting the angiogenic protein fibroblast growth factor-3 (FGF-3). The area fraction score in control rats treated with compound 48/80 was 0.31+/-0.03, and this was reduced to 0.07+/-0.01 by suramin (P < 0.05). After i.p. administration of FGF-3 the area fraction score was reduced by suramin from 0.29+/-0.03 to 0.05+/-0.01 (P < 0.05). These results provide evidence that suramin exerts inhibitory effects on angiogenesis in both in vitro and in vivo models.

Metabolism of 6-mercaptopurine in the erythrocytes, liver, and kidney of rats during multiple-dose regimens.

PURPOSE: To describe the metabolism of 6-mercaptopurine (6-MP) in erythrocytes and tissues of rats after repeated administration of 6-MP at two dose levels and to provide evidence that in vivo modulation of 6-MP anabolism can be obtained by simultaneous treatment with ribavirin or hydroxyurea, two inhibitors of enzymes involved in the bioactivation of 6-MP to the active 6-thioguanine nucleotides (6-TGN). METHODS: Rats were treated i.p. with 6-MP at 12.5 and 25 mg/kg daily for 12 days and erythrocyte, liver, and kidney levels of 6-mercaptopurine nucleotides (6-MPN) and 6-TGN were investigated during the accumulation phase and for 50 days after the end of treatment. In combination studies, ribavirin at 75 and 100 mg/kg per day (for 6-MP, 25 and 12.5 mg/kg per day) or hydroxyurea at 200 mg/kg per day were given i.p. for 12 days. The measurements of thionucleotide levels in rat samples were performed by high-pressure liquid chromatography (HPLC). RESULTS: The maximal concentration (Cmax) and the area under the concentration versus time curve (AUC) of 6-MPN and 6-TGN in erythrocytes and tissues increased significantly after the administration of 6-MP at 25 mg/kg per day as compared with 12.5 mg/kg per day. In particular, the Cmax and AUC of 6-TGN in erythrocytes of rats treated with 6-MP at 25 mg/kg per day were approximately 5-fold higher than the 6-TGN values observed following treatment at 12.5 mg/kg per day. Moreover, 6-TGN levels in erythrocytes were significantly higher than those of 6-MPN (910.9+/-53.1 and 286.8+/-23.4 pmol/8 x 10(8) cells for 6-TGN and 6-MPN, respectively, P < 0.05) after treatment with 6-MP at 25 mg/kg per day. The administration of ribavirin, an inhibitor of inosine monophosphate dehydrogenase, in association with 6-MP increased the amount of 6-MPN detected in erythrocytes and tissues while reducing 6-TGN levels in samples. The production and accumulation of 6-MPN and 6-TGN were increased in erythrocytes and tissues by hydroxyurea, an inhibitor of ribonucleotide reductase. Finally, a significant correlation between thionucleotide concentrations and erythrocyte counts was observed. CONCLUSION: The overall results demonstrate that 6-MP is actively metabolized in rats and that its biotransformation can be modulated by agents acting on enzymes of the purine metabolism, resulting in significant changes in erythrocyte and tissue levels of 6-MPN and 6-TGN. These findings provide evidence that the rat is a suitable model for investigation of the metabolism of 6-MP and its possible pharmacologic modulation.