Differentiating megakaryocytes in myelodysplastic syndromes succumb to mitochondrial derangement without caspase activation

Myelodysplastic syndromes (MDS) constitute a preneoplastic condition in which potentially malignant cancer stem cells continuously die during differentiation. This MDS-associated cell death often involves caspase-3 activation, yet can also occur without caspase activation, for instance in differentiating megakaryocytes (MK). We investigated, the mechanisms through which MK from MDS patients undergo premature cell death. While polyploid, mature MK from healthy subjects or MDS patients manifested caspase-3 activation during terminal differentiation, freshly isolated, immature MK from MDS died without caspase-3 activation. Similarly, purified bone marrow CD34⁺ cells from MDS patients that were driven into MK differentiation in vitro died without caspase-3 activation at an immature stage, before polyploidization. The premature death of MDS MK was accompanied by the mitochondrial release of cytochrome c, Smac/DIABLO and endonuclease G, a caspase-independent death effector, as well loss of the mitochondrial membrane potential and plasma membrane phosphatidylserine exposure before definitive loss of viability. Thus, a stereotyped pattern of mitochondrial alterations accompanies differentiation-associated MK death in MDS. T. Braun and G. Carvalho contributed equally to this paper.     

Bayesian evidence synthesis for a transmission dynamic model for HIV among men who have sex with men

Understanding infectious disease dynamics and the effect on prevalence and incidence is crucial for public health policies. Disease incidence and prevalence are typically not observed directly and increasingly are estimated through the synthesis of indirect information from multiple data sources. We demonstrate how an evidence synthesis approach to the estimation of human immunodeficiency virus (HIV) prevalence in England and Wales can be extended to infer the underlying HIV incidence. Diverse time series of data can be used to obtain yearly "snapshots" (with associated uncertainty) of the proportion of the population in 4 compartments: not at risk, susceptible, HIV positive but undiagnosed, and diagnosed HIV positive. A multistate model for the infection and diagnosis processes is then formulated by expressing the changes in these proportions by a system of differential equations. By parameterizing incidence in terms of prevalence and contact rates, HIV transmission is further modeled. Use of additional data or prior information on demographics, risk behavior change and contact parameters allows simultaneous estimation of the transition rates, compartment prevalences, contact rates, and transmission probabilities.     

Asymmetry of Leg Use During Prey Handling in the Spider Scytodes globula (Scytodidae)

In spitting spiders Scytodes globula collected in the field, anterior leg loss was more frequent on the left than on the right side, possibly as an outcome of predatory episodes. A laboratory study was performed in which intact adult females of S. globula were placed with individuals from three species of recluse spiders, Loxosceles intermedia, L. gaucho, and L. laeta. The frequency of probing touches by spitting spiders to their prey was significantly higher with left leg I than with right leg I. Left leg II and right leg II also differed in touching frequency, but in a less marked way. The results, which may represent the first evidence of behavioral laterality in a spider species, suggest that behavioral asymmetry may be an ancient evolutionary trait.     

Development of microsatellite markers for the grapevine fungal pathogen Phaeomoniella chlamydospora

Twenty polymorphic microsatellite markers from microsatellite-enriched genomic DNA of the grapevine fungal pathogen, Phaeomoniella chlamydospora, were developed and characterized. The markers were used to genotype isolates from Australia and from Europe/Eurasia. The number of alleles per locus ranged from two to 11. Gene diversity per locus ranged from 0.08 to 0.63 among Australian isolates, and from 0.2 to 0.77 among isolates from Europe/Eurasia, demonstrating the suitability of these markers for population genetic studies of P. chlamydospora. Eighteen of the 20 markers also amplified a product in the closely related Phaeoacremonium aleophilum.     

The mononuclear cell in human blood which mediates antibody-dependent cellular cytotoxicity to virus-infected target cells. II. Identification as a K cell.

Studies were carried out to determine whether the mononuclear cell in human blood which mediates antibody-dependent cellular cytotoxicity (ADCC) to herpes simplex virus (HSV)-infected target cells has surface Fc receptors which participate in the reaction. The F (ab')2 fragment of human IgG antibody was inactive both in ADCC and in complement-mediated cytolysis, but retained the capacity to neutralize infectious virus, to agglutinate erythrocytes coated with viral antigens, and to bind to the surface of virus-infected cells. Treatment of sensitized virus-infected target cells with staphylococcus protein A, which has affinity for the Fc epitope of IgG, strongly reduced their susceptibility to lysis by ADCC in a dose-dependent relationship. These findings indicate that the Fc portion of IgG antibody to the virus is necessary for cytotoxicity. Treatment of blood mononuclear cells with either heat-aggregated gamma-globulin or HSV immune complexes inhibited effector cell activity. The presence of "third party" cellular immune complexes also strongly inhibited ADCC. Adsorption of mononuclear cells to plastic surfaces coated with soluble third party immune complexes resulted in a significant reduction in effector cell activity. These findings demonstrate that the ADCC effector cell possesses surface Fc receptors which are utilized in the ADCC reaction. The presence of Fc receptors on the surface of the effector cell indicates that it is a K cell rather than a null cell.     

Possibilities of vaccine manufacture in human diploid cell strains with a serum replacement factor.

Cell lines MDCK (canine kidney), BGM (Buffalo green monkey kidney) and human embryonic lung fibroblast will support viral growth efficiently in medium without serum. Both MRC-5 and WI-38 cell strains have been approved by the Food and Drug Administration for manufacturing viral vaccines against cytomegalovirus and varicella-zoster virus. In this study we examine these two cell lines and viruses for their ability to grow in medium containing a serum replacement. The serum substitute used is LPSR-1 (low protein serum replacement). Using LPSR-1 in defined medium, we demonstrate multipassage cell growth and viral cultivation and replication equivalent to those obtained in medium containing fetal bovine serum (FBS). Viral growth after complete elimination of FBS varies and depends on cell line and virus. Serum substitutes can eliminate FBS in the viral growth phase of vaccine production and reduce costs.     

Multidrug resistance-associated protein-1 (MRP1) genetic variants,MRP1 protein levels and severity of COPD

Background

Multidrug resistance-associated protein-1 (MRP1) protects against oxidative stress and toxic compounds generated by cigarette smoking, which is the main risk factor for chronic obstructive pulmonary disease (COPD). We have previously shown that single nucleotide polymorphisms (SNPs) in MRP1 significantly associate with level of FEV₁ in two independent population based cohorts. The aim of our study was to assess the associations of MRP1 SNPs with FEV₁ level, MRP1 protein levels and inflammatory markers in bronchial biopsies and sputum of COPD patients.

Methods

Five SNPs (rs212093, rs4148382, rs504348, rs4781699, rs35621) in MRP1 were genotyped in 110 COPD patients. The effects of MRP1 SNPs were analyzed using linear regression models.

Results

One SNP, rs212093 was significantly associated with a higher FEV₁ level and less airway wall inflammation. Another SNP, rs4148382 was significantly associated with a lower FEV₁ level, higher number of inflammatory cells in induced sputum and with a higher MRP1 protein level in bronchial biopsies.

Conclusions

This is the first study linking MRP1 SNPs with lung function and inflammatory markers in COPD patients, suggesting a role of MRP1 SNPs in the severity of COPD in addition to their association with MRP1 protein level in bronchial biopsies.     

Association mapping for wood quality and growth traits in Eucalyptus globulus ssp. globulus Labill identifies nine stable marker-trait associations for seven traits

The moderate to high levels of nucleotide diversity and low linkage disequilibrium found in many forest tree species make them ideal candidates for association mapping. Here, we report candidate gene-based association mapping results for complex wood quality and growth traits in Eucalyptus globulus Labill. ssp. globulus, the most widely grown eucalypt in temperate regions of the world. Ninety-eight single nucleotide polymorphisms (SNPs) from 20 wood quality candidate genes were assayed in a discovery population consisting of 385 trees sourced from a provenance-progeny trial. Twenty-five selected SNPs with significant associations (P?.