Potentiation of the anti-tumour effects of Photofrin®-based photodynamic therapy by localized treatment with G-CSF

Photofrin®-based photodynamic therapy (PDT) has recently been approved for palliative and curative purposes in cancer patients. It has been demonstrated that neutrophils are indispensable for its anti-tumour effectiveness. We decided to evaluate the extent of the anti-tumour effectiveness of PDT combined with administration of granulocyte colony-stimulating factor (G-CSF) as well as the influence of Photofrin®and G-CSF on the myelopoiesis and functional activity of neutrophils in mice. An intensive treatment with G-CSF significantly potentiated anti-tumour effectiveness of Photofrin®-based PDT resulting in a reduction of tumour growth and prolongation of the survival time of mice bearing two different tumours: colon-26 and Lewis lung carcinoma. Moreover, 33% of C-26-bearing mice were completely cured of their tumours after combined therapy and developed a specific and long-lasting immunity. The tumours treated with both agents contained more infiltrating neutrophils and apoptotic cells then tumours treated with either G-CSF or PDT only. Importantly, simultaneous administration of Photofrin®and G-CSF stimulated bone marrow and spleen myelopoiesis that resulted in an increased number of neutrophils demonstrating functional characteristics of activation. Potentiated anti-tumour effects of Photofrin®-based PDT combined with G-CSF observed in two murine tumour models suggest that clinical trials using this tumour therapy protocol would be worth pursuing. © 2000 Cancer Research Campaig

The Zakłodzie enstatite meteorite: Mineralogy, petrology, origin, and classification

The Zakłodzie meteorite was found in September 1998, about 40 km west of Zamość, in southeast Poland. Macroscopic and microscopic observations (in transmitted and reflected light), microprobe analyses, cathodoluminescence images, and X-ray diffraction data show that the meteorite is composed of clino- and orthoenstatite, two generations of feldspars, relict olivine (forsterite), a polymorph of SiO2 (apparently cristobalite), and opaque minerals: Fe-Ni alloy (kamacite and taenite), troilite, schreibersite, graphite, and sulfide (Mg, Mn, Fe)S, which is probably keilite. The texture is fine- to inequigranular of cumulate type, locally intergranular. The MgS-FeS thermometer indicates that the sulfides crystallized at ~580-600 degrees C. Thus, the Zakłodzie meteorite formed by the nearly complete melting of an enstatite chondrite protolith, probably at ~4.4 Ga; the process was likely caused by the decay of the 26Al nuclide in the planetesimal interior. The second stage of its evolution, which could have happened at ~2.1 Ga, involved partial re-melting of most fusible components, probably due to collision with another body. The structure, composition, and origin of the meteorite and its relation to the parent rock indicate that Zakłodzie may represent a primitive enstatite achondrite.The Meteoritics & Planetary Science archives are made available by the Meteoritical Society and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202

What is at risk? – an environmental health risk assessment related with pharmaceutical substances in drinking water

Constantly increasing rate of drugs’ consumption can be related with environmental abundance of drug substances and their degradation products. Unused and used drugs are often discharged into municipal wastewaters or landfills. Wastewater treatment plants are not able to remove the entire load of drugs. Especially those which occur occasionally or at very low concentrations. Therefore, a variety of pharmaceuticals occur in surface and drinking water sources. A chronic low-level exposure to drugs occurring in a water environment can cause: antibiotic resistance, allergic reactions (eg. Penicillin), cause carcinogenesis (oxytetracycline, furazolidone), nephropathy (gentamicin) and have a negative impact on the natural human intestinal microflora. Therefore, it is not an easy task to assess a common human health effects related with chronic exposure to low doses of active pharmaceutical substances. Nonetheless, such knowledge seems essential in order to undertake preventive actions that would substantially decrease the level of health risk

Petrology of the Baszkówka L5 chondrite: A record of surface-forming processes on the parent body

We review the petrology of Baszkówka, present new microprobe data on mineral constituents, and propose a model for surface properties of the parent body consistent with these data. The low shock index and high porosity of the Baszkówka L5 chondrite mean that considerable primary textural and petrographic detail is preserved, allowing insight into the structure and evolution of the parent body. This meteorite formed in a sedimentary environment resembling that in which pyroclastic rocks are deposited. The origin of the component chondrules, achondritic fragments (mostly olivine and pyroxene aggregates), chondritic-achondritic aggregates, and compound chondrules can be explained by invoking collision of 2 melted or partially melted planetesimals, each covered with a thin crust. This could have happened at an early stage in the evolution of the solar system, between 1 and 2 Myr after its origin. The collision resulted in the formation of a cloud containing products of earlier magmatic crystallization (chondrite and achondrite fragments) from which new chondrules were created. Particle collision in this cloud produced fragmented chondrules, chondritic-achondritic aggregates, and compound chondrules. Within this low-density medium, these particles were accreted on the surface of the larger of the planetesimals involved in the collision. The density of the medium was low enough to prevent grain-size sorting of the components but high enough to prevent the total loss of heat and to enable the welding of fragments on the surface of the body. The rock material was homogenized within the cloud and, in particular, within the zone close to the planetesimal surface. The hot material settled on the surface and became welded as molten or plastic metal, and sulfide components cemented the grains together. The process resembled the formation of welded ignimbrites. Once these processes on the planetesimal surface were completed, no subsequent recrystallization occurred. The high porosity of the Baszkówka chondrite indicates that the meteorite comes from a near-surface part of the parent body. Deeper parts of the planetesimal would have been more massive because of compaction.The Meteoritics & Planetary Science archives are made available by the Meteoritical Society and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202