Comparison of risk stratification tools in predicting outcomes of patients with higher-risk myelodysplastic syndromes treated with azanucleosides

Established prognostic tools in patients with myelodysplastic syndromes (MDS) were largely derived from untreated patient cohorts. Although azanucleosides are standard therapies for higher-risk (HR)-MDS, the relative prognostic performance of existing prognostic tools among patients with HR-MDS receiving azanucleoside therapy is unknown. In the MDS Clinical Research Consortium database, we compared the prognostic utility of the International Prognostic Scoring System (IPSS), revised IPSS (IPSS-R), MD Anderson Prognostic Scoring System (MDAPSS), World Health Organization-based Prognostic Scoring System (WPSS) and the French Prognostic Scoring System (FPSS) among 632 patients who presented with HR-MDS and were treated with azanucleosides as the first-line therapy. Median follow-up from diagnosis was 15.7 months. No prognostic tool predicted the probability of achieving an objective response. Nonetheless, all five tools were associated with overall survival (OS, P=0.025 for the IPSS, P=0.011 for WPSS and P<0.001 for the other three tools). The corrected Akaike Information Criteria, which were used to compare OS with the different prognostic scoring systems as covariates (lower is better) were 4138 (MDAPSS), 4156 (FPSS), 4196 (IPSS-R), 4186 (WPSS) and 4196 (IPSS). Patients in the highest-risk groups of the prognostic tools had a median OS from diagnosis of 11-16 months and should be considered for up-front transplantation or experimental approaches.

Acoustical properties of selected tissue phantom materials for ultrasound imaging

This note summarizes the characterization of the acoustic properties of four materials intended for the development of tissue, and especially breast tissue, phantoms for the use in photoacoustic and ultrasound imaging. The materials are agar, silicone, polyvinyl alcohol gel (PVA) and polyacrylamide gel (PAA). The acoustical properties, i.e., the speed of sound, impedance and acoustic attenuation, are determined by transmission measurements of sound waves at room temperature under controlled conditions. Although the materials are tested for application such as photoacoustic phantoms, we focus here on the acoustic properties, while the optical properties will be discussed elsewhere. To obtain the acoustic attenuation in a frequency range from 4 MHz to 14 MHz, two ultrasound sources of 5 MHz and 10 MHz core frequencies are used. For preparation, each sample is cast into blocks of three different thicknesses. Agar, PVA and PAA show similar acoustic properties as water. Within silicone polymer, a significantly lower speed of sound and higher acoustical attenuation than in water and human tissue were found. All materials can be cast into arbitrary shapes and are suitable for tissue-mimicking phantoms. Due to its lower speed of sound, silicone is generally less suitable than the other presented materials.

Underphosphorylated BAD interacts with diverse antiapoptotic Bcl-2 family proteins to regulate apoptosis

Survival factors activate kinases which, in turn, phosphorylate the proapoptotic Bcl-xl/Bcl-2-associated death promoter homolog (BAD) protein at key serine residues. Phosphorylated BAD interacts with 14-3-3 proteins, and overexpression of 14-3-3 attenuates BAD-mediated apoptosis. Although BAD is known to interact with Bcl-2, Bcl-w, and Bcl-xL, the exact relationship between BAD and anti- or proapoptotic Bcl-2 proteins has not been analyzed systematically. Using the yeast two-hybrid protein interaction assay, we found that BAD interacted negligibly with proapoptotic Bcl-2 proteins. Even though wild type BAD only interacted with selected numbers of antiapoptotic proteins, underphosphorylated mutant BAD interacted with all antiapoptotic Bcl-2 proteins tested (Bcl-2, Bcl-w, Bcl-xL, Bfl-1/A1, Mcl-1, Ced-9, and BHRF-1). Using nonphosphorylated recombinant BAD expressed in bacteria, direct interactions between BAD and diverse antiapoptotic Bcl-2 members were also observed. Furthermore, apoptosis induced by BAD was blocked by coexpression with Bcl-2, Bcl-w, and Bfl-1. Comparison of BAD orthologs from zebrafish to human indicated the conservation of a 14-3-3 binding site and the BH3 domain during evolution. Thus, highly conserved BAD interacts with diverse antiapoptotic Bcl-2 members to regulate apoptosis.

Characterization of two fly LGR (leucine-rich repeat-containing, G protein-coupled receptor) proteins homologous to vertebrate glycoprotein hormone receptors: constitutive activation of wild-type fly LGR1 but not LGR2 in transfected mammalian cells

The receptors for lutropin (LH), FSH, and TSH belong to the large G protein-coupled receptor (GPCR) superfamily and are unique in having a large N-terminal extracellular (ecto-) domain important for interactions with the large glycoprotein hormone ligands. Recent studies indicated the evolution of a large family of the leucine-rich repeat-containing, G protein-coupled receptors (LGRs) with at least seven members in mammals. Based on the sequences of mammalian glycoprotein hormone receptors, we have identified a new LGR in Drosophila melanogaster and named it as fly LGR2 to distinguish it from the previously reported fly LH/FSH/TSH receptor (renamed as fly LGR1). Genomic analysis indicated the presence of 10 exons in fly LGR2 as compared with 16 exons in fly LGR1. The deduced fly LGR2 complementary DNA (cDNA) showed 43 and 64% similarity to the fly LGR1 in the ectodomain and transmembrane region, respectively. Comparison of 12 LGRs from diverse species indicated that these proteins can be divided into three subfamilies and fly LGR1 and LGR2 belong to different subfamilies. Potential signaling mechanisms were tested in human 293T cells overexpressing the fly receptors. Of interest, fly LGR1, but not LGR2, showed constitutive activity as reflected by elevated basal cAMP production in transfected cells. The basal activity of fly LGR1 was further augmented following point mutations of key residues in the intracellular loop 3 or transmembrane VI, similar to those found in patients with familial male precocious puberty. The present study reports the cloning of fly LGR2 and indicates that the G protein-coupling mechanism is conserved in fly LGR1 as compared with the mammalian glycoprotein hormone receptors. The characterization of fly receptors with features similar to mammalian glycoprotein hormone receptors allows a better understanding of the evolution of this unique group of GPCRs and future elucidation of their ligand signaling mechanisms.

Physical activity and functional capacity measurement in women: a report from the NHLBI-sponsored WISE study

Physical activity and functional capacity have not been assessed by questionnaire for criterion validity in women. We wished to evaluate the ability of a physical activity and a functional capacity assessment questionnaire to predict functional capacity measured by treadmill exercise stress testing, as well as correlate with cardiac risk factors and angiographic coronary artery disease (CAD) in women. In a National Heart, Lung and Blood Institute (NHLBI)-sponsored cross-sectional population study involving four academic medical centers, 476 women with cardiac risk factors undergoing coronary angiography for evaluation for suspected myocardial ischemia were enrolled in the Women's Ischemia Syndrome Evaluation (WISE). The main outcome measures were functional capacity measured during symptom-limited exercise treadmill testing, cardiac risk factors, and CAD, using core laboratory-determined measures. Physical activity measured by the Postmenopausal Estrogen and Progesterone Intervention physical activity questionnaire (PEPI-Q) and functional capacity measured by the Duke Activity Status Index (DASI) questionnaire, correlated with functional capacity measured in metabolic equivalents (METS), as estimated during symptom-limited exercise treadmill testing (r = 0.27, p = 0.001 and r = 0.31, p = 0. 0002, respectively). The DASI was a significant independent predictor of functional capacity even after adjustment for cardiac risk factors, and the PEPI-Q was not. The DASI and PEPI-Q scores were inversely associated with higher numbers and levels of cardiac risk factors, as well as angiographic CAD. The DASI questionnaire is a reasonable correlate of functional capacity achieved during symptom-limited treadmill exercise testing in women with suspected myocardial ischemia. Lower functional capacity or physical activity measured by the DASI and PEPI-Q, respectively, is associated with more prevalent cardiac risk factors and angiographic CAD. These findings suggest that the DASI and, to a lesser extent, the PEPI-Q have criterion validity for use in health-related research in women.

[Endophthalmitis after cataract surgery: predisposing factors, infectious agents and therapy]

BACKGROUND

Infectious exogenous endophthalmitis is a serious complication after cataract surgery. Despite modern pharmacological and surgical methods, its treatment is still difficult.

PATIENTS AND METHODS

In a retrospective study the records of all patients treated for endophthalmitis following cataract extraction at the Department of Ophthalmology of the University Hospital in Hamburg between January 1989 and December 1997 were assessed.

RESULTS

Of 36 patients treated for endophthalmitis, 29 (80.6%) had been referred. In 14 (38.9%) of these 29 patients endophthalmitis had occurred after outpatient cataract surgery. Seven patients (19.4%) had been treated as inpatients at the University Eye Hospital Eppendorf. Vitrectomy was performed in 80.6% of the cases. An infectious agent was isolated from 50% of diagnostic probes. The most common organism isolated were coagulase-negative staphylococci (4 cases). Predisposing factors for the development of endophthalmitis were diabetes (27.8%), intraoperative loss of vitreous (19.4%), application of systemic steroids (13.9%) and wound dehiscence (11.1%). Of 27 patients (75%) followed up, 16 (59.3%) had a final visual acuity of 20/400 or better (mean 20/40). An enucleation had to be performed in 4 patients (13.8%).

CONCLUSION

In this study, approximately 60% of patients with endophthalmitis following cataract extraction had their globes preserved and a good visual outcome after appropriate surgical interventions.