The Economic Impact of Agriculture and Other Industries in Texas.

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Model of the meniscus of an ionic liquid ion source.

A simple model of the transfer of charge and ion evaporation in the meniscus of an ionic-liquid ion source working in the purely ionic regime is proposed on the basis of order-of-magnitude estimates which show that, in this regime, _i_ the flow in the meniscus is dominated by the viscosity of the liquid and is affected very little by the mass flux accompanying ion evaporation, and _ii_ the effect of the space charge around the evaporating surface is negligible and the evaporation current is controlled by the finite electrical conductivity of the liquid. The model predicts that a stationary meniscus of a very polar liquid undergoing ion evaporation is nearly hydrostatic and can exist only below a certain value of the applied electric field, at which the meniscus attains its maximum elongation but stays smooth. The electric current vs applied electric field characteristic displays a frozen regime of negligible ion evaporation at low fields and a conduction-controlled regime at higher fields, with a sharp transition between the two regimes owing to the high sensitivity of the ion evaporation rate to the electric field. A simplified treatment of the flow in the capillary or liquid layer through which liquid is delivered to the meniscus shows that the size of the meniscus decreases and the maximum attainable current increases when the feeding pressure is decreased, and that appropriate combinations of feeding pressure and pressure drop may lead to high maximum currents

Three dimensional optic tissue culture and process

A process for artificially producing three-dimensional optic tissue has been developed. The optic cells are cultured in a bioreactor at low shear conditions. The tissue forms normal, functional tissue organization and extracellular matrix

Cetuximab and irinotecan as third-line therapy in advanced colorectal cancer patients: a single centre phase II trial

The epidermal growth factor receptor (EGFR), which participates in signalling pathways that are deregulated in cancer cells, is frequently mutated in colorectal-cancer cells. Cetuximab is a monoclonal antibody that specifically blocks the EGFR. We evaluated the efficacy of cetuximab in weekly combination with irinotecan in metastatic colorectal cancer patients refractory to previous treatments based on oxaliplatin or irinotecan. We included 55 heavily pretreated patients (colon/rectum: 34/11, M/F: 16/29, median age 63 years, range: 27–79) whose disease had progressed during or within an oxaliplatin-based first-line chemotherapy and a irinotecan-based second-line regimen. Patients were followed for tumour response and were also evaluated for the time to tumour progression, and safety of treatment. Cetuximab was given at an initial dose of 400 mg m−2, followed by weekly infusions of 250 mg m−2. Irinotecan was administered weekly at the dose of 90 mg m−2. All patients were assessable for treatment efficacy and safety response rate was 25.4% (95% CI: 21.7–39.6%); 38.2% (95 CI: 18.6–39.8%) of patients showed a disease stability as the best response. As a consequence, the overall tumour control rate was 63.6% (95% CI: 46.4–70.6%). The median time to progression was 4.7 months (95% CI: 2.5–7.1 months) and the median survival time was 9.8 months (95% CI: 3.9–10.1 months). The most common G3-4 noncutaneous side toxicities were: diarrhoea (16.4%), fatigue (12.7%) and stomatitis (7.3%). 89.1% of patients developed skin toxicity and 32.6% of cases was of grade 3–4. No allergic reactions were identified at any courses in any patients. Fever was documented in 27.3% of patients and was most commonly recorded after the first administration. Cetuximab has clinically significant activity even in heavily pretreated colorectal cancer patients progressed after both oxaliplatin and irinotecan-based chemotherapy regimens

The in vivo properties of STX243: a potent angiogenesis inhibitor in breast cancer

The steroidal-based drug 2-ethyloestradiol-3,17-O,O-bis-sulphamate (STX243) has been developed as a potent antiangiogenic and antitumour compound. The objective of this study was to ascertain whether STX243 is more active in vivo than the clinically relevant drug 2-methoxyoestradiol (2-MeOE2) and the structurally similar compound 2-MeOE2-3,17-O,O-bis-sulphamate (STX140). The tumour growth inhibition efficacy, antiangiogenic potential and pharmacokinetics of STX243 were examined using four in vivo models. Both STX243 and STX140 were capable of retarding the growth of MDA-MB-231 xenograft tumours (72 and 63%, respectively), whereas no inhibition was observed for animals treated with 2-MeOE2. Further tumour inhibition studies showed that STX243 was also active against MCF-7 paclitaxel-resistant tumours. Using a Matrigel plug-based model, in vivo angiogenesis was restricted with STX243 and STX140 (50 and 72%, respectively, using a 10 mg kg−1 oral dose), thereby showing the antiangiogenic activity of both compounds. The pharmacokinetics of STX243 were examined at two different doses using adult female rats. The compound was orally bioavailable (31% after a single 10 mg kg−1 dose) and resistant to metabolism. These results show that STX243 is a potent in vivo drug and could be clinically effective at treating a number of oncological conditions

Intermediate and high-mass ion beams from a 10-cm Duopigatron

Experimental studies of a 10-cm Duopigatron as a source of argon, krypton, and xenon ion beams are reported. Source plasma instabilities are examined, and the mass dependence of oscillation frequencies and instability onset conditions are determined. Arc current and density oscillations are found to be associated with ion acoustic fluctuations with frequencies scaling as 1/M 1/2 . Langmuir probe measurements within the source plasma double layer are used to indicate the physical mechanism responsible for the observed large-amplitude are current shifts. Ion beams have been extracted at energies up to 18 kV, and drain currents up to 540 mA for argon, 440 mA for krypton, and 520 mA for xenon have been achieved with source plasma densities in the range 10 11 –10 12 cm –3 . Excellent agreement with existing theoretical models has been obtained in the mass and density dependence of the extraction current, as well as the voltage at which transition from space-charge limited to ion saturation emission occurs.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45476/1/11090_2004_Article_BF00647189.pd

Cetuximab potentiates oxaliplatin cytotoxic effect through a defect in NER and DNA replication initiation

Preclinical studies have demonstrated that the chemotherapeutic action of oxaliplatin, a third generation platinum derivative, is improved when combined with cetuximab, a monoclonal antibody inhibitor of epidermal growth factor receptors. To explore the mechanism of this synergistic benefit, we used HCT-8 and HCT-116, two human colon cancer cell lines, respectively, responsive and non-responsive to the oxaliplatin/cetuximab combination. We examined the effect of drug exposure on glutathione-S-transferase-mediated oxaliplatin detoxification, DNA–platinum adducts formation, cell cycle distribution, apoptosis, and the expression of multiple targets involved in DNA replication, recombination, and repair. The major changes we found in HCT-8 were a stimulation of oxaliplatin–DNA adduct formation associated with reduced expression of the key enzyme (excision repair cross complementation group1: ERCC1) in the key repair process of oxaliplatin–DNA platinum adduct, the nucleotide excision repair (NER), both at the mRNA and protein levels. We also observed a reduced expression of factors involved in DNA replication initiation, which correlates with an enrichment of cells in the G1 phase of the cell cycle as well as an acceleration of apoptosis. None of these changes occurred in the non-responsive HCT-116 cell that we used as a negative control. These findings support the fact that cetuximab potentiates the oxaliplatin-mediated cytotoxic effect as the result of inhibition of NER and also DNA replication initiation

Enhanced tumour antiangiogenic effects when combining gefitinib with the antivascular agent ZD6126

Current experimental and clinical knowledge supports the optimisation of endothelial cell targeting using a strategy combining anti-EGFR drugs with antivascular agents. The purpose of the present study was to examine the effects of the association of ZD6126, an antivascular microtubule-destabilising agent, with gefitinib and irradiation on the growth of six head and neck human cancer cell lines xenografted in nude mice and to study predictive and molecular factors responsible for antitumour effects. CAL33- and Hep-2-grafted cell lines were the most sensitive to ZD6126 treatment, with VEGF levels significantly higher (P=0.0336) in these tumour xenografts compared to Detroit 562- and CAL27-grafted cell lines with relatively low VEGF levels that were not sensitive to ZD6126. In contrast, neither IL8 levels nor EGFR expression was linked to the antitumour effects of ZD6126. ZD6126 in combination with gefitinib resulted in a synergistic cytotoxic interaction with greater antitumour effects than gefitinib alone. The synergistic interaction between ZD6126 and gefitinib was corroborated by a significant decrease in CD31 labelling. The present study may serve for future innovative clinical applications, as it suggests that VEGF tumour levels are possible predictors for ZD6126 antitumour efficacy. It also supports the notion of antitumour supra-additivity when combining gefitinib and ZD6126, and identifies neoangiogenesis as the main determinant of this synergistic combination

Rapid copper acquisition by developing murine mesothelioma: Decreasing bioavailable copper slows tumor growth, normalizes vessels and promotes T cell infiltration

Copper, an essential trace element acquired through nutrition, is an important co-factor for pro-angiogenic factors including vascular endothelial growth factor (VEGF). Decreasing bioavailable copper has been used as an antiangiogenic and anti-cancer strategy with promising results. However, the role of copper and its potential as a therapy in mesothelioma is not yet well understood. Therefore, we monitored copper levels in progressing murine mesothelioma tumors and analyzed the effects of lowering bioavailable copper. Copper levels in tumors and organs were assayed using atomic absorption spectrophotometry. Mesothelioma tumors rapidly sequestered copper at early stages of development, the copper was then dispersed throughout growing tumor tissues. These data imply that copper uptake may play an important role in early tumor development. Lowering bioavailable copper using the copper chelators, penicillamine, trientine or tetrathiomolybdate, slowed in vivo mesothelioma growth but did not provide any cures similar to using cisplatin chemotherapy or anti-VEGF receptor antibody therapy. The impact of copper lowering on tumor blood vessels and tumor infiltrating T cells was measured using flow cytometry and confocal microscopy. Copper lowering was associated with reduced tumor vessel diameter, reduced endothelial cell proliferation (reduced Ki67 expression) and lower surface ICAM/CD54 expression implying reduced endothelial cell activation, in a process similar to endothelial normalization. Copper lowering was also associated with a CD4+ T cell infiltrate. In conclusion, these data suggest copper lowering is a potentially useful anti-mesothelioma treatment strategy that slows tumor growth to provide a window of opportunity for inclusion of other treatment modalities to improve patient outcomes