Tumor dormancy and cell signaling: anti-mu-induced apoptosis in human B-lymphoma cells is not caused by an APO-1-APO-1 ligand interaction.

Signal transduction initiated by crosslinking of antigen-specific receptors on T- and B-lymphoma cells induces apoptosis. In T-lymphoma cells, such crosslinking results in upregulation of the APO-1 ligand, which then interacts with induced or constitutively expressed APO-1, thereby triggering apoptosis. Here we show that crosslinking the membrane immunoglobulin on human lymphoma cells (Daudi) (that constitutively express APO-1) does not induce synthesis of APO-1 ligand. Further, a noncytotoxic fragment of anti-APO-1 antibody that blocks T-cell-receptor-mediated apoptosis in T-lymphoma cells does not block anti-mu-induced apoptosis. Hence, in B-lymphoma cells, apoptosis induced by signaling via membrane IgM is not mediated by the APO-1 ligand.

The BCL2 major breakpoint region is a sequence- and cell-cycle-specific binding site of the Ku antigen.

The majority of translocations involving BCL2 are very narrowly targeted to three breakpoint clusters evenly spaced over a 100-bp region of the gene's terminal exon. We have recently shown that the immediate upstream boundary of this major breakpoint region (mbr) is a specific recognition site for single-strand DNA (ssDNA) binding proteins on the sense and antisense strands. The downstream flank of the mbr is a helicase binding site. In this report we demonstrate that the helicase and ssDNA binding proteins show reciprocal changes in binding activity over the cell cycle. The helicase is maximally active in G1 and early S phases; the ssDNA binding proteins are maximally active in late S and G2/M phases. An inhibitor of helicase binding appears in late S and G2/M. Finally, at least one component of the helicase binding complex is the Ku antigen. Thus, a protein with helicase activity implicated in repair of double-strand breaks, variable (diversity) joining recombination, and, potentially, cell-cycle regulation is targeted to the BCL2 mbr.

A cooperative model for receptor recognition and cell adhesion: evidence from the molecular packing in the 1.6-A crystal structure of the pheromone Er-1 from the ciliated protozoan Euplotes raikovi.

The crystal structure of the pheromone Er-1 from the unicellular eukaryotic organism Euplotes raikovi was determined at 1.6 A resolution and refined to a crystallographic R factor of 19.9%. In the tightly packed crystal, two extensive intermolecular helix-helix interactions arrange the Er-1 molecules into layers. Since the putative receptor of the pheromone is a membrane-bound protein, whose extracellular C-terminal domain is identical in amino acid sequence to the soluble pheromone, the interactions found in the crystal may mimic the pheromone-receptor interactions as they occur on a cell surface. Based on this, we propose a model for the interaction between soluble pheromone molecules and their receptors. In this model, strong pheromone-receptor binding emerges as a consequence of the cooperative utilization of several weak interactions. The model offers an explanation for the results of binding studies and may also explain the adhesion between cells that occurs during mating.

Regulated expression of the obese gene product (leptin) in white adipose tissue and 3T3-L1 adipocytes.

A mutation within the obese gene was recently identified as the genetic basis for obesity in the ob/ob mouse. The obese gene product, leptin, is a 16-kDa protein expressed predominantly in adipose tissue. Consistent with leptin's postulated role as an extracellular signaling protein, human embryonic kidney 293 cells transfected with the obese gene secreted leptin with minimal intracellular accumulation. Upon differentiation of 3T3-L1 preadipocytes into adipocytes, the leptin mRNA was expressed concomitant with mRNAs encoding adipocyte marker proteins. A factor(s) present in calf serum markedly activated expression of leptin by fully differentiated 3T3-L1 adipocytes. A 16-hr fast decreased (by approximately 85%) the leptin mRNA level of adipose tissue of lean (ob/+ or +/+) mice but had no effect on the approximately 4-fold higher level in obese (ob/ob) littermates. Since the mutation at the ob locus fails to produce the functional protein, yet its cognate mRNA is overproduced, it appears that leptin is necessary for its own downregulation. Leptin mRNA was also suppressed in adipose tissue of rats during a 16-hr fast and was rapidly induced during a 4-hr refeeding period. Insulin deficiency provoked by streptozotocin also markedly down-regulated leptin mRNA and this suppression was rapidly reversed by insulin. These results suggest that insulin may regulate the expression of leptin.

Immunohistochemical evidence of synaptic retraction, cytoarchitectural remodeling, and cell death in the inner retina of the rat model of Oygen-Induced Retinopathy (OIR)

Purpose. Postnatal exposure to hyperoxia destroys the plexiform layers of the neonatal rat retina, resulting in significant electroretinographic anomalies. The purpose of this study was to identify the mechanisms at the origin of this loss. Methods. Sprague-Dawley (SD) and Long Evans (LE) rats were exposed to hyperoxia from birth to postnatal day (P) 6 or P14 and from P6 to P14, after which rats were euthanatized at P6, P14, or P60. Results. At P60, synaptophysin staining confirmed the lack of functional synaptic terminals in SD (outer plexiform layer [OPL]) and LE (OPL and inner plexiform layer [IPL]) rats. Uneven staining of ON-bipolar cell terminals with mGluR6 suggests that their loss could play a role in OPL thinning. Protein kinase C(PKC)-α and recoverin (rod and cone ON-bipolar cells, respectively) showed a lack of dendritic terminals in the OPL with disorganized axonal projections in the IPL. Although photoreceptor nuclei appeared intact, a decrease in bassoon staining (synaptic ribbon terminals) suggests limited communication to the inner retina. Findings were significantly more pronounced in LE rats. An increase in TUNEL-positive cells was observed in LE (inner nuclear layer [INL] and outer nuclear layer [ONL]) and SD (INL) rats after P0 to P14 exposure (425.3%, 102.2%, and 146.3% greater than control, respectively [P < 0.05]). Conclusions. Results suggest that cell death and synaptic retraction are at the root of OPL thinning. Increased TUNEL-positive cells in the INL confirm that cells die, at least in part, because of apoptosis. These findings propose a previously undescribed mechanism of cell death and synaptic retraction that are likely at the origin of the functional consequences of hyperoxia.

Digital Fabrication and Free Culture. One More Minor Becoming?

Diferentes autores se refieren a la fabricación digital como la Tercera Revolución Digital, después de las revoluciones de la computación y la comunicación. Como ocurriera con las dos revoluciones precedentes, se generaron grandes expectativas en torno a las virtualidades políticas de estas nuevas tecnologías para dar lugar a relaciones de producción más libres e individuos más autónomos. Sin embargo, como también ocurriera con la computación y la comunicación, lo que realmente está ocurriendo demuestra que las supuestas virtualidades no llegarán a hacerse actuales sin una intensa implicación, organización y trabajo por parte de sectores activistas técnicos y sociales. Se discute el caso de la compra corporativa de la empresa pionera de hardware libre Makerbot, como ejemplo de la situación y punto de inflexión en las expectativas de los nuevos tecno-visionarios. Para concluir se propone una serie de posibles estrategias que podrían promover el desarrollo efectivo de un ecosistema libre y open source de fabricación digital.

Acculturation and material culture - George I. Quimby, Curator of Exhibits, Department of Anthropology, and Alexander Spoehr, Curator, Oceanic Ethnology.

v.36:no.6(1951)

Nunivak Island Eskimo (Yuit) technology and material culture / James W. VanStone.

n.s. no.12(1989)

The other side of protest music: the extreme-right and skinhead culture in democratic Portugal (1974-2015)

Although Portugal does not have a significant radical right presence in its party system, in the last decades the country did witness the development of a neo-Nazi skinhead movement that expresses its white nationalist nature and goals through the musical genres of Rock Against Communism (RAC) and the related Oi!. Utilizing various historical sources and theoretical analysis, this study contextualizes the development of nationalist music in Portugal, both before and especially during the democratic period (1974-2015). It focuses on its protagonists, domestic and international networks, as well as on the few attempts to establish a common cause with radical right-wing political parties at the turn of the century and in present times.

Judicial Selection, Lay Participation, and Judicial Culture in the Czech Republic: A Study in a Central European (Non)Transformation. College of Europe Research Paper in Law 03/2014

Introduction. The idea that “merit” should be the guiding principle of judicial selections is a universal principle, unlikely to be contested in whatever legal system. What differs considerably across legal cultures, however, is the way in which “merit” is defined. For deeper cultural and historical reasons, the current definition of “merit” in the process of judicial selections in the Czech Republic, at least in the way it is implemented in the institutional settings, is an odd mongrel. The old technocratic Austrian judicial heritage has in some aspects merged with, in others was altered or destroyed, by the Communist past. After 1989, some aspects of the judicial organisation were amended, with the most problematic elements removed. Furthermore, several old as well as new provisions relating to the judiciary were struck down by the Constitutional Court. However, apart from these rather haphazard interventions, there has been neither a sustained discussion as to how a new judicial architecture and system of judicial appointments ought to look like nor much of broader, conceptual reform in this regard. Thus, some twenty five years after the Velvet Revolution of 1989, the guiding principles for judicial selection and appointments are still a debate to be had.