Cytogenetic findings in mouse multiple myeloma and Waldenström's macroglobulinemia

Multiple myeloma (MM) and Waldenström's macroglobulinemia-like lymphoma (MW) appear spontaneously in C57BL/KaLwRij mice at a frequency of 0.5% and 0.2%, respectively. They can readily be propagated by intravenous transfer of mainly bone marrow or spleen cells into syngeneic recipients. Previous studies demonstrated that these mouse malignant monoclonal gammopathies (MMG) show clinical and biologic features that closely resemble those of the corresponding human diseases and thus could be used as experimental models. We report on cytogenetic analysis of two mouse MW and five MM in vivo cell lines of the 5TMM series propagated in syngeneic mice. These studies demonstrated clonal abnormalities in all cell lines, hyperdiploid karyotype in both MW and one MM lines, and hypotriploidy, hypertriploidy, or hypotetraploidy in the other lines. Structural abnormalities of chromosome 15 were observed in all MM lines. In the five MM lines, frequent rearrangements were also found for chromosome numbers 1, 2, 5, and 12. A single chromosomal abnormality, as found in induced mouse plasmacytomas and resembling Burkitt lymphoma, was not found in mouse MM and MW. It was concluded that spontaneously originating C57BL MM of the 5T series is a better model for human MM than pristane-induced BALB/c or NZB plasmacytoma

Follow-up of bone lesions in an experimental multiple myeloma mouse model: description of an in vivo technique using radiography dedicated for mammography.

The evolution of bone lesions in transplantable C57BL/KaLwRjj 5T mouse myeloma (MM) has been followed in vivo. Mice were anaesthetised and a radiograph of the pelvis and hind legs was performed by a radiograph dedicated for mammography. This is the first description of an in vivo technique under experimental conditions whereby the development of bone lesions owing to the MM growth was demonstrated

Generic Tasks of Scientific Discovery

Abstract The aim of this paper is conceptual and theoretical: to propose the concept of generic scientific task as an organizing principle for research on scientific discovery, or more broadly, scientific inference. Generic tasks cut across various scientific fields, but involve rather specific inferences; in any case, their generality is found only by surveying science as a whole. Computer programs that carry out these generic tasks may differ somewhat from one science to another, but they all share similar computational mechanisms: hence they represent generic tasks. We assemble a broad array of previous work as evidence to support this concept, and work out the research plan and methods that are implied by it

Dopaminergic Control of Striatal Cholinergic Interneurons Underlies Cocaine-Induced Psychostimulation

Cocaine drastically elevates dopamine (DA) levels in the striatum, a brain region that is critical to the psychomotor and rewarding properties of the drug. DA signaling regulates intrastriatal circuits connecting medium spiny neurons (MSNs) with afferent fibers and interneurons. While the cocaine-mediated increase in DA signaling on MSNs is well documented, that on cholinergic interneurons (ChIs) has been more difficult to assess. Using combined pharmacological, chemogenetic, and cell-specific ablation approaches, we reveal that the D2R-dependent inhibition of acetylcholine (ACh) signaling is fundamental to cocaine-induced changes in behavior and the striatal genomic response. We show that the D2R-dependent control of striatal ChIs enables the motor, sensitized, and reinforcing properties of cocaine. This study highlights the importance of the DA- and D2R-mediated inhibitory control of ChIs activity in the normal functioning of striatal networks

Impact of high carbon amendments and pre-crops on soil bacterial communities

A 2-year outdoor mesocosm experiment was carried out to determine the effects of high C amendments (HCAs; wheat straw and sawdust) compared to a control with no addition of HCAs (no-HCA) and 2 different crop rotation systems (spring barley/winter barley and faba bean/winter barley) on soil bacterial communities using a molecular barcoding approach. Samples were analyzed after pre-crop harvest (T1) and harvest of winter barley (T2). Our data demonstrate a clear drop in bacterial diversity after winter barley harvest in the no-HCA and wheat straw treatment compared to the pre-crops. Sawdust application had a stabilizing effect on bacterial diversity compared to the pre-crops and induced an increase in carbon (C) stocks in soil which were however negatively correlated with yields. Main responders in the no-HCA and wheat straw treatment compared to the pre-crops were bacteria of the phyla Actinobacteria and Bacteroidetes which were enriched and bacteria belonging to Firmicutes, Gemmatimonadetes, Proteobacteria, and Gemmatimonadaceae which were depleted. Overall differences between wheat straw-amended and no-HCA control samples were small and included single ASVs from various phyla. In sawdust-amended samples, only a shift of some Proteobacteria families was observed compared to the no-HCA control. Overall, pre-crop plant species had small influence on the observed response pattern of the soil microbiome towards the amendments and was only visible for wheat straw

[89Zr]Oxinate4 for long-term in vivo cell tracking by positron emission tomography

Purpose 111In (typically as [111In]oxinate3) is a gold standard radiolabel for cell tracking in humans by scintigraphy. A long half-life positron-emitting radiolabel to serve the same purpose using positron emission tomography (PET) has long been sought. We aimed to develop an 89Zr PET tracer for cell labelling and compare it with [111In]oxinate3 single photon emission computed tomography (SPECT). Methods [89Zr]Oxinate4 was synthesised and its uptake and efflux were measured in vitro in three cell lines and in human leukocytes. The in vivo biodistribution of eGFP-5T33 murine myeloma cells labelled using [89Zr]oxinate4 or [111In]oxinate3 was monitored for up to 14 days. 89Zr retention by living radiolabelled eGFP-positive cells in vivo was monitored by FACS sorting of liver, spleen and bone marrow cells followed by gamma counting. Results Zr labelling was effective in all cell types with yields comparable with 111In labelling. Retention of 89Zr in cells in vitro after 24 h was significantly better (range 71 to >90 %) than 111In (43–52 %). eGFP-5T33 cells in vivo showed the same early biodistribution whether labelled with 111In or 89Zr (initial pulmonary accumulation followed by migration to liver, spleen and bone marrow), but later translocation of radioactivity to kidneys was much greater for 111In. In liver, spleen and bone marrow at least 92 % of 89Zr remained associated with eGFP-positive cells after 7 days in vivo. Conclusion [89Zr]Oxinate4 offers a potential solution to the emerging need for a long half-life PET tracer for cell tracking in vivo and deserves further evaluation of its effects on survival and behaviour of different cell types

Versatile thiol-based reactions for micrometer- and nanometer-scale photopatterning of polymers and biomolecules

Thiol-based chemistry provides a mild and versatile tool for surface functionalization. In the present work, mercaptosilane films were patterned by utilizing UV-induced photo-oxidation of the thiol to yield sulfonate groups via contact and interferometric lithography (IL). These photo-generated sulfonic acid groups were used for selective immobilization of amino-functionalized molecules after activation with triphenylphosphine ditriflate (TPPDF). Moreover, protein-resistant poly(oligoethyleneglycolmethacrylate) (POEGMA) brushes were grown from the intact thiol groups by a surface-induced polymerization reaction. Exploiting both reactions it is possible to couple amino-labelled nitrilotriacetic acid (NH2-NTA) to sulfonate-functionalized regions, enabling the site-specific binding of green fluorescent protein (GFP) to regions defined lithographically, while exploiting the protein-resistant character of POEGMA brushes to prevent non-specific protein adsorption to previously masked areas. The outstanding reactivity of thiol groups paves the way towards novel strategies for the fabrication of complex protein nanopatterns beyond thiol–ene chemistry

N-Terminal Prolactin-Derived Fragments, Vasoinhibins, Are Proapoptoptic and Antiproliferative in the Anterior Pituitary

The anterior pituitary is under a constant cell turnover modulated by gonadal steroids. In the rat, an increase in the rate of apoptosis occurs at proestrus whereas a peak of proliferation takes place at estrus. At proestrus, concomitant with the maximum rate of apoptosis, a peak in circulating levels of prolactin is observed. Prolactin can be cleaved to different N-terminal fragments, vasoinhibins, which are proapoptotic and antiproliferative factors for endothelial cells. It was reported that a 16 kDa vasoinhibin is produced in the rat anterior pituitary by cathepsin D. In the present study we investigated the anterior pituitary production of N-terminal prolactin-derived fragments along the estrous cycle and the involvement of estrogens in this process. In addition, we studied the effects of a recombinant vasoinhibin, 16 kDa prolactin, on anterior pituitary apoptosis and proliferation. We observed by Western Blot that N-terminal prolactin-derived fragments production in the anterior pituitary was higher at proestrus with respect to diestrus and that the content and release of these prolactin forms from anterior pituitary cells in culture were increased by estradiol. A recombinant preparation of 16 kDa prolactin induced apoptosis (determined by TUNEL assay and flow cytometry) of cultured anterior pituitary cells and lactotropes from ovariectomized rats only in the presence of estradiol, as previously reported for other proapoptotic factors in the anterior pituitary. In addition, 16 kDa prolactin decreased forskolin-induced proliferation (evaluated by BrdU incorporation) of rat total anterior pituitary cells and lactotropes in culture and decreased the proportion of cells in S-phase of the cell cycle (determined by flow cytometry). In conclusion, our study indicates that the anterior pituitary production of 16 kDa prolactin is variable along the estrous cycle and increased by estrogens. The antiproliferative and estradiol-dependent proapoptotic actions of this vasoinhibin may be involved in the control of anterior pituitary cell renewal