Comparative antioxidant, prooxidant and cytotoxic activity of sigmoidin A and eriodictyol

Sigmoidin A (SGN) is a prenylated flavanone derivative of eriodictyol (ERD) with reported moderate antioxidant, antimicrobial and anti-inflammatory activity. Since ERD and other structurally similar antioxidant phenolic compounds have been shown to induce prooxidative macromolecular damage and cytotoxicity in cancer cells, the comparative in vitro effects of these structural analogues on cancer cell viability and Cu(II)-dependent DNA damage were studied. In the presence of Cu(II) ions, both SGN and ERD (7.4-236 µM) caused comparable concentration-dependent pBR322 plasmid DNA strand scission. The DNA damage induced by SGN and ERD could be abolished by ROS scavengers, glutathione (GSH) and catalase as well as EDTA and a specific Cu(I) chelator neocuproine. Both ERD and SGN readily reduce Cu(II) to Cu(I) suggesting a prooxidative mechanism of DNA damage. In a cell free system, ERD and SGN did also show comparable radical scavenging activity. SGN was, however, by an order of magnitude more cytotoxic to cancer cells than ERD and this effect was significantly attenuated by GSH suggesting a prooxidative mechanism of cell death. A depletion of intracellular GSH level by SGN in cancer cells is also demonstrated.

Triterpenoid saponins from the cytotoxic root extract of Sideroxylon foetidissimum, an endemic Yucatecan medicinal plant

The flora of the Yucatan peninsula (Mexico) includes approximately 3000 plant species. Sideroxylon foetidissimum Jacq. subsp. gaumeri (Sapotaceae) is an endemic plant to the Yucatan peninsula; its fruit is edible and local people use the plant for medicinal purposes, although no details on its preparation or application are available [1,2]. A preliminary cytotoxic evaluation of the ethanolic root extract of S. foetidissimum revealed a potent activity against murine macrophage like cell line RAW 264.7 (IC50=39.54±4.11µg/mL). The systematic bioassay-guided fractionation of the extract resulted in the identification of the active saponin-containing fraction (IC50=33.69±6.19µg/mL). Four new triterpenoid saponins and a 1:1 mixture of two saponins were isolated from the active saponin- containing fraction. The evaluation of their cytotoxic activity revealed no activity for the tested pure saponins; however, the 1:1 mixture of saponins showed a potent activity (IC50=11.91±1.49µg/mL). The isolation of the saponins was carried out using semi-preparative HPLC. The structural assignments of the pure saponins were based on 1D (1H and 13C and DEPT-135) and 2D (COSY, HMBC, HSQC and TOCSY) NMR and mass spectrometry analyses. In this presentation, the isolation, identification and cytotoxic activity of the isolated compounds is discussed in more detail.

Epilobium parviflorum Schreb. - in vitro study of biological action

Epilobium parviflorum Schreb. (Onagraceae) is used for the treatment of benign prostatic hyperplasia (BPH), which is regarded as an endocrine disorder caused by age-related hormone imbalance and increased oxidative damage [1,2,3]. Epilobium can moderate the obstructive and the irritative symptoms of BPH [1] but its biological action is not entirely identified. E. parviflorum is rich in phytosterols, flavonoids (myricetin, quercetin, kaempferol and their glycosides), phenolic acids, catechins, ellagi- and gallotannins [4]. The potential biological effects of Epilobium parviflorum Schreb. have been investigated, in respect to its antioxidant, anti-inflammatory, enzyme-inhibitory and anti-androgenic effect. The whole-plant water extract showed higher antioxidant effect (IC50=1.65±0.05µg/mL) in DPPH assay than Trolox or ascorbic acid and inhibited the lipid peroxidation examined in TBA assay (IC50=2.31±0.18mg/mL). In concentrations 0.20-15.00µg/mL the extract possessed a protective effect comparable to catalase enzyme (2500 IU/mL), against oxidative damage generated on fibroblast cells. The examination of the COX-inhibitory effect showed that E. parviflorum had an anti-inflammatory effect (IC50=1.38±0.08µg/mL). Investigation of steroid receptor binding ability and the aromatase enzyme-inhibition showed negative results in the concentration range examined.

Molybdenum hexacarbonyl and DBU reduction of nitro compounds under microwave irradiation

An ethanolic mixture of molybdenurn hexacarbonyl and DBU mediates the reduction of nitroarenes to the corresponding anilines in excellent yields in 15-30 minutes under microwave irradiation.

Contributions to the bryological flora of the tropical and subtropical forests from the Argentina (Bryophyta, Musci).

The authors present here a list of 32 mosses belonging to 15 families: Brachytheciaceae, Cryphaeaceae, Entodontaceae, Hedwigiaceae, Hypnaceae, Leptodontaceae, Meteoriaceae, Neckeraceae, Pilotrichaceae, Polytrichaceae, Pterobryaceae, Racopilaceae, Rigodiaceae, Stereophyllaceae, and Trachypodaceae, all collected in the mountainous forests of the Yungas of the NW of the Argentina (Jujuy, Salta, Catamarca and Tucumán provinces), and also in the rainforests from the NE of the country (Misiones province). Eight species: Atrichum polycarpum, Chrysohypnum elegantulum, Pilosium chlorophyllum, Pilotrichella flexilis, Porotrichodendron lindigii, Pseudotrachypus martinicensis, Steerecleus scariosus, and Thamnobryum fasciculatum are new records for the bryologic flora from Argentina. Braunia imberbis and Squamidium brasiliense are two new records for the bryophytic flora of the Catamarca province; Porotrichodendron superbum is new for the Salta province, while Forsstroemia coronata is the first record for the Catamarca and Jujuy provinces. Aerolindigia capillacea, Braunia reflexifolia, Chryso-hypnum diminutivum, Meteorium deppei and Meteoridium remotifolium are five new citations for the Jujuy province, and Schoenobryum concavifolium is new for the bryophytic flora of the Misiones province. Many studied species occur more frequently in the Yungas than in the NE rainforests; others show separated distribution but live in both areas, the Yungas and Paranaense area, and others are more or less restricted to the Paranaense rainforest of the NE of Argentina. The taxonomy of species is updated, and comments are included on bibliographical precedents, ecology and chorology of each taxon.

Investigation of the effect of intrauterine inflammation and infection on fetal brain injury using human and animal models

In recent years, increased focus has been placed on the role of intrauterine infection and inflammation in the pathogenesis of fetal brain injury leading to neurodevelopmental disorders such as cerebral palsy. At present, the mechanisms by which inflammatory processes during pregnancy cause this effect on the fetus are poorly understood. Our previous work has indicated an association between experimentally-induced intrauterine infection, increased proinflammatory cytokines, and increased white matter injury in the guinea pig fetus. In order to further elucidate the pathways by which inflammation in the maternal system or the fetal membranes leads to fetal impairment, a number of studies investigating aspects of the disease process have been performed. These studies represent a body of work encompassing novel research and results in a number of human and animal studies. Using a guinea pig model of inflammation, increased amniotic fluid proinflammatory cytokines and fetal brain injury were found after a maternal inflammatory response was initiated using endotoxin. In order to more closely monitor the fetal response to chorioamnionitis, a model using the chronically catheterized fetal ovine was carried out. This study demonstrated the adverse effects on fetal white matter after intrauterine exposure to bacterial inoculation, though the physiological parameters of the fetus were relatively stable throughout the experimental protocol, even when challenged with intermittent hypoxic episodes. The placenta is an important mediator between mother and fetus during gestation, though its role in the inflammatory process is largely undefined. Studies on the placental role in the inflammatory process were undertaken, and the limited ability of proinflammatory cytokines and endotoxin to cross the placenta are detailed herein. Neurodevelopmental disorders can be monitored in animal models in order to determine effective disease models for characterization of injury and use in therapeutic strategies. Our characterizations of postnatal behaviour in the guinea pig model using motility monitoring and spatial memory testing have shown small but significant differences in pups exposed to inflammatory processes in utero. The data presented herein contributes a breadth of knowledge to the ongoing elucidation of the pathways by which fetal brain injury occurs. Determining the pathway of damage will lead to discovery of diagnostic criteria, while determining the vulnerabilities of the developing fetus is essential in formulating therapeutic options.

A phase 2 study of high-activity 186Re-HEDP with autologous peripheral blood stem cell transplant in progressive hormone-refractory prostate cancer metastatic to bone

Purpose: We investigated the potential for improvement in disease control by use of autologous peripheral blood stem cell transplant (PBSCT) to permit administration of high activities of 186Re-hydroxyethylidene diphosphonate (HEDP) in patients with progressive hormone-refractory prostate cancer (HRPC).

Methods: Eligible patients had progressive HRPC metastatic to bone, good performance status and minimal soft tissue disease. Patients received 5,000 MBq of 186Re-HEDP i.v., followed 14 days later by PBSCT. Response was assessed using PSA, survival, pain scores and quality of life.

Results: Thirty-eight patients with a median age of 67 years (range 50–77) and a median PSA of 57 ng/ml (range 4–3,628) received a median activity of 4,978 MBq 186Re-HEDP (range 4,770–5,100 MBq). The most serious toxicity was short-lived grade 3 thrombocytopenia in 8 (21%) patients. The median survival of the group is 21 months (95%CI 18–24 months) with Kaplan-Meier estimated 1- and 2-year survival rates of 83% and 40% respectively. Thirty-one patients (81%, 95% CI 66–90%) had stable or reduced PSA levels 3 months post therapy while 11 (29%, 95% CI 15–49%) had PSA reductions of >50% lasting >4 weeks. Quality of life measures were stable or improved in 27 (66%) at 3 months.

Conclusion: We have shown that it is feasible and safe to deliver high-activity radioisotope therapy with PBSCT to men with metastatic HRPC. Response rates and survival data are encouraging; however, further research is needed to define optimal role of this treatment approach.

A new look at the pulsating DB white dwarf GD 358: Line-of-sight velocity measurements and constraints on model atmospheres

We report on our findings of the bright, pulsating, helium atmosphere white dwarf GD 358, based on time-resolved optical spectrophotometry. We identify 5 real pulsation modes and at least 6 combination modes at frequencies consistent with those found in previous observations. The measured Doppler shifts from our spectra show variations with amplitudes of up to 5.5 km s-1 at the frequencies inferred from the flux variations. We conclude that these are variations in the line-of-sight velocities associated with the pulsational motion. We use the observed flux and velocity amplitudes and phases to test theoretical predictions within the convective driving framework, and compare these with similar observations of the hydrogen atmosphere white dwarf pulsators (DAVs). The wavelength dependence of the fractional pulsation amplitudes (chromatic amplitudes) allows us to conclude that all five real modes share the same spherical degree, most likely, l=1. This is consistent with previous identifications based solely on photometry. We find that a high signal-to-noise mean spectrum on its own is not enough to determine the atmospheric parameters and that there are small but significant discrepancies between the observations and model atmospheres. The source of these remains to be identified. While we infer Teff =24 kK and log g ~ 8.0 from the mean spectrum, the chromatic amplitudes, which are a measure of the derivative of the flux with respect to the temperature, unambiguously favour a higher effective temperature, 27 kK, which is more in line with independent determinations from ultra-violet spectra.

De la cooperativa agroalimentaria a la "learning netchain". Hacia un planteamiento teorico interorganizativo e interpersonal

Se propone un planteamiento teórico/conceptual para determinar si las relaciones interorganizativas e interpersonales de la netchain de las cooperativas agroalimentarias evolucionan hacia una learning netchain. Las propuestas del trabajo muestran que el mayor grado de asociacionismo y la mayor cooperación/colaboración vertical a lo largo de la cadena están positivamente relacionados con la posición horizontal de la empresa focal más cercana del consumidor final. Esto requiere una planificación y una resolución de problemas de manera conjunta, lo que está positivamente relacionado con el mayor flujo y diversidad de la información/conocimiento obtenido y diseminado a lo largo de la netchain. Al mismo tiempo se necesita desarrollar un contexto social en el que fluya la información/conocimiento y las nuevas ideas de manera informal y esto se logra con redes personales y, principalmente, profesionales y con redes internas y, principalmente, externas. Todo esto permitirá una mayor satisfacción de los socios de la cooperativa agroalimentaria y de sus distribuidores y una mayor intensidad en I+D, convirtiéndose la netchain de la cooperativa agroalimentaria, así, en una learning netchain.

Purification capacity of a highly loaded laboratory scale tidal flow reed bed system with effluent recirculation

The purification capacity of a laboratory scale tidal flow reed bed system with final effluent recirculation at a ratio of 1:1 was investigated in this study. In particular, this four-stage reed bed system was highly loaded with strong agricultural wastewater. Under the hydraulic and organic loading rates as high as 0.43 m3/m2d and 1055 gCOD/m2d, respectively, the average removal efficiencies of COD, BOD5, SS, NH4-N and P were 77%, 78%, 66%, 62% and 38%. Even with the high loading rates, approximately 30% of NH4-N was converted into NO2-N and NO3-N from the mid-stage of the system where nitrification took place. The results suggest that the multi-stage reed bed system could be employed to treat strong wastewater under high loading, especially for the substantive mass removal of solids, organic matter and ammoniacal-nitrogen. Tidal flow combined with effluent recirculation is a favourable operation strategy to achieve this objective.