Involvement of endoplasmic reticulum stress in Docetaxel-induced JNK-dependent apoptosis of human melanoma

Our previous studies revealed that Docetaxel-induced apoptosis of melanoma cells is entirely dependent on activation of the JNK signalling pathway. Here, we show that Docetaxel-induced apoptosis is mediated by induction of ER stress. This was shown by Docetaxel-induced activation of proteins involved in ER stress signalling namely GRP78, ATF6, IRE1α, and PERK/eIF2α. Knockdown of IRE1α by siRNA markedly inhibited Docetaxel-induced JNK activation and downstream targets of JNK indicating that activation of IRE1α was upstream of activation of the JNK. Co-immunoprecipitation experiments showed that activation of JNK is due to activation of ASK1 through formation of an IRE1α-TRAF2-ASK1 complex. ER stress mediated activation of the JNK pathway is downstream of activation of PKCδ in that downregulation of PKCδ expression using specific PKCδ siRNA significantly inhibited Docetaxel-induced activation of IRE1α and the JNK pathway. These findings provide new insights to understand the mode of action of taxanes in treatment of human melanoma.     

The architecture of a middleware layer for controlling the quality of multimedia sessions

Collaborative multimedia systems demand overall session quality control beyond the level of Quality of Service (QoS) as pertaining to individual streams in isolation of others. To this end, we have recently introduced the concept of Quality of Session (QoSess) control. At every instant in time, the quality of the session depends on the actual QoS offered by the system to each of the application streams, as well as on the relative priorities of these streams according to the application semantics. In this paper, we present the architecture of a middleware layer for controlling the quality of a session. In addition, we describe the inter-stream bandwidth adaptation mechanisms, which are used by the QoSess layer to dynamically control the bandwidth shares of the streams belonging to a session. This revised version was published online in July 2006 with corrections to the Cover Date.     

Synthesis and biological activity of some unsaturated 6-azauracil acyclonucleosides

A useful route is described for obtaining Z and E unsaturated alkylating agents 3 and 4. Coupling 6-azauracils 5 and 6 with unsaturated alkylating agent followed by the deprotection with H+ resin gave acyclonucleosides 11-14 in good overall yields. Unsaturated acyclonucleosides phosphonates 19 and 20 were prepared using potassium carbonate as base and 4-bromobut-2-enyl diethyl phosphonate 16 as the alkylating agent. The introduction of a propargyl group at the N-3 position of acyclonucleosides 7, 8 17, 18, 19, and 20 was achieved using potassium carbonate in DMF.     

Case report: A large extramedullary granulocytic sarcoma as the initial presenting feature of chronic myeloid leukemia

Granulocytic sarcomas (chloromas) are rare extramedullary tumors consisting of primitive granulocytic cells. They arise de novo, or are associated with other hematologic disorders such as acute myeloid leukemia, myelodysplastic syndrome, or myeloproliferative disorders. We report here on a case of a 62-year-old woman who presented with a large swelling in her right groin and leg. The mass was confirmed by biopsy to be a granulocytic sarcoma. Bone marrow examination showed mild hypercellularity but no evidence of increase in blast count. However, cytogenetic examination of the marrow showed t(9;22), indicating an unexpected diagnosis of chronic myeloid leukemia.     

Changes in content and fatty acid profiles of total lipids and sulfolipids in the halophyte Crithmum maritimum under salt stress

In the halophyte Crithmum maritimum, the sulfolipid content increased considerably in the presence of NaCl. There were no significant changes in the total fatty acid composition of sulfolipids during salt treatment, except for linoleic and linolenic acids. In comparison to the control plants, sulfolipids in NaCl-treated plants showed a decrease in the percentage of unsaturated fatty acid (C18:3), and a corresponding increase in the percentage of unsaturated fatty acids (C18:2). As a whole, the data reported in this work suggest that sulfolipds may be one important aspect of strategies involved in salt tolerance of this halophyte.     

Differentiation of acute and chronic myeloid leukemic blasts into the dendritic cell lineage: analysis of various differentiation-inducing signals

Purpose: Ex vivo differentiation of myeloid leukemic blasts into dendritic cells (DCs) holds significant promise for use as cellular vaccines, as they may present a constellation of endogenously expressed known and unknown leukemia antigens to the immune system. Although variety of stimuli can drive leukemiaDC differentiation in vitro, these blast-derived DCs typically have aberrant characteristics compared with DCs generated from normal progenitors by the same stimuli. It is not clear whether this is due to underlying leukemogenic mechanisms (e.g., specific oncogenes), genetic defects, stage of maturation arrest, defects in cytokine receptor expression or signal transduction pathways, or whether different stimuli themselves induce qualitatively dissimilar DC differentiation. Methods: To assess what factors may contribute to aberrant leukemic blastDC differentiation, we have examined how the same leukemic blasts (AML and CML) respond to different DC differentiation signals—including extracellular (the cytokine combination GM-CSF+TNF-+IL-4) and intracellular (the protein kinase C agonist PMA, the calcium ionophore A23187, and the combination of PMA plus A23187) stimuli. Results: We have found that the same leukemic blasts will develop qualitatively different sets of DC characteristics in response to differing stimuli, although no stimuli consistently induced all of the characteristic DC features. There were no clear differences in the responses relative to specific oncogene expression or stage of maturation arrest (AML vs CML). Signal transduction agonists that bypassed membrane receptors/proximal signaling (in particular, the combination of PMA and A23187) consistently induced the greatest capability to activate T cells. Interestingly, this ability did not clearly correlate with expression of MHC/costimulatory ligands. Conclusions: Our findings suggest that signal transduction may play an important role in the aberrant DC differentiation of leukemic blasts, and demonstrate that direct activation of PKC together with intracellular calcium signaling may be an effective method for generating immunostimulatory leukemia-derived DCs.This work was supported by NIH CA85208, CA95829, and ASCO Young Investigator Award (M.A.K-D)     

Choice of recipient vessels in delayed TRAM flap breast reconstruction after radiotherapy

This study compared the use of the internal mammary and thoracodorsal recipient vessels in a uniform group of patients who underwent delayed TRAM flap reconstruction after radiotherapy, focusing on usability rates and outcomes. The authors identified 123 delayed TRAM flap patients who had undergone postmastectomy radiotherapy from a prospective database (1990 to 2001). Recipient vessel unusability rates were calculated on the basis of reports of inspection of a vessel, either by direct intraoperative dissection or by findings from color Doppler examination (internal mammary vessels only). Charts were reviewed for outcomes including flap loss, vascular complications, fat necrosis, and lymphedema; t-test and chi-square analyses were performed to compare outcomes and unusability rates, and multiple regression analysis was performed to determine factors influencing outcome. Of the 123 planned free TRAM flaps, 106 were completed as free flaps and 17 were performed as pedicled flaps because of unusable recipient vessels. Of the free flaps, 45 were anastomosed to the internal mammary vessels, 55 to the thoracodorsal vessels, and six to other vessels. The internal mammary and thoracodorsal groups did not differ significantly in body mass index, abdominal scars, smoking history, time delay between irradiation and TRAM flap reconstruction, or flap ischemia time. Radiation doses to the axilla (thoracodorsal), internal mammary chain, and supraclavicular fossa were similar between the groups. The internal mammary vessels were rejected in 11 (20 percent) of 56 cases, and the thoracodorsal vessels were rejected in 19 (26 percent) of 74 cases (p = 0.42). In cases with unusable internal mammary vessels, 46 percent (n = 5) had inadequate veins, 27 percent (n = 3) had inadequate arteries, and in 27 percent (n = 3) both vessels were inadequate. In the 19 cases with unusable thoracodorsal vessels, 84 percent (n = 16) were excessively scarred, 11 percent (n = 2) had inadequate vessels, and 5 percent (n = 1) were absent. Outcomes were similar regardless of recipient vessels used (internal mammary versus thoracodorsal): total flap loss, 0 percent versus 4 percent (p = 0.20); vascular complications, 6.7 percent versus 11 percent (p = 0.46); arm lymphedema, 4.4 percent versus 9 percent (p = 0.37); partial flap loss, 9 percent versus 6 percent (p = 0.54); and fat necrosis, 18 percent versus 15 percent (p = 0.69). Multivariate analysis revealed a trend for higher complication rates in smokers and with the use of the thoracodorsal vessels as the recipients. Overall, no discernible unusability or outcome differences were detected between the internal mammary and thoracodorsal groups.     

Spines and neurite branches function as geometric attractors that enhance protein kinase C action

Ca2+ and diacylglycerol-regulated protein kinase Cs (PKCs; conventional PKC isoforms, such as PKCgamma) are multifunctional signaling molecules that undergo reversible plasma membrane translocation as part of their mechanism of activation. In this article, we investigate PKCgamma translocation in hippocampal neurons and show that electrical or glutamate stimulation leads to a striking enrichment of PKCgamma in synaptic spines and dendritic branches. Translocation into spines and branches was delayed when compared with the soma plasma membrane, and PKCgamma remained in these structures for a prolonged period after the response in the soma ceased. We have developed a quantitative model for the translocation process by measuring the rate at which PKCgamma crossed the neck of spines, as well as cytosolic and membrane diffusion coefficients of PKCgamma. Our study suggests that neurons make use of a high surface-to-volume ratio of spines and branches to create a geometric attraction process for PKC that imposes a delayed enhancement of PKC action at synapses and in peripheral processes.     

Keratinophilic Fungi Recovered from Muddy Soil in Cairo Vicinities,Egypt

One hundred samples of muddy soil were collected from seven areas in the vicinity of Cairo and screened for the presence of keratinophilic fungi by using hair baiting isolation technique. Forty isolates of keratinophilic fungi were recovered and identified by recognition of their cultures, macro- and micromorphological features. Their physiological and molecular characteristics were studied by determination of their ubiquinone (Coenzyme Q) composition and DNA sequences of (ITS1-5.8S-ITS2) and 18S rRNA region sequences. The Keratinophilic isolates were identified as Chrysosporium carmichaelii, C. queenslandicum, C. zonatum, C. indicum, Aphanoascus mephitalis, and Uncinocarpus reesii. Chrysosporium zonatum was the most prevalent species and represented 42.5% of the total number of isolates. Each of C. carmichaelii and C. queenslandicum were equal in their prevalence and represented 15%. C. indicum comes next constituting 12.5%; followed by Uncinocarpus reesii which represented 10%. The least prevalent species in our study was Aphanoascus mephitalis, which was represented only 5% of the total keratinophilic isolates.