Detection of BCR-ABL kinase domain mutations in CD34+ cells from newly diagnosed chronic phase CML patients and their association with imatinib resistance

BCR-ABL kinase domain (KD) mutations, the most common cause of imatinib resistance, are infrequently detected in newly diagnosed chronic-phase chronic myeloid leukemia (CP-CML) patients. Recent studies indicate pre-existing mutations (PEMs) can be detected in a higher percentage of CML patients using CD34+ stem/progenitor cells, and these mutations may correlate with imatinib resistance. We investigated KD mutations in CD34+ stem cells from 100 CP-CML patients by multiplex ASO-PCR and sequencing ASO-PCR products at the time of diagnosis. PEMs were detected in 32/100 patients and included F311L, M351T, and T315I. After a median follow-up of 30 months (range 8-48), all patients with PEMs exhibited imatinib resistance. Of 68 patients without PEMs, 24 developed imatinib resistance. Mutations were detected in 21 of these patients by ASO-PCR and KD sequencing. All 32 patients with PEMs had the same mutations. In imatinib-resistant patients without PEMs, we detected F311L, M351T, Y253F, and T315I mutations. All imatinib-resistant patients without T315I and Y253F mutations responded to imatinib dose escalation. In conclusion, BCR-ABL PEMs can be detected in a substantial number of CP-CML patients when investigated using CD34+ stem/progenitor cells. These mutations are associated with imatinib resistance, and mutation testing using CD34+ cells may facilitate improved, patient-tailored treatment

Foreign Direct Investment, Aggregate Demand Conditions and Exchange Rate Nexus: A Panel Data Analysis of BRICS Economies

In this study, we attempt to provide underlying theoretical and empirical explanations for exchange rate appreciation due to foreign capital influx and aggregate demand conditions in the BRICS economies. The empirical analysis is based on a panel dataset of BRICS countries over the time period 1992–2013 to substantiate our theoretical findings. For panel co-integration, Pedroni and Johansen-Fisher panel co-integration tests are conducted to compare co-integration among panel countries. We also analyze the results from Dumitrescu-Hurlin panel causality test among variables and use Granger Causality to test for the causal patterns in each of the individual countries. Our findings showed that the exchange rate volatility is directly affected by the flows of FDI, GDP per capita, Capital formulation and House hold consumption. The results have profound implications in terms of exchange rate stability in the BRICS countries and associated risks

Internal Absorption and Foreign Direct Investment Inflows: A new approach towards Market Size

Abstract. In continuation of the efforts to understand the dynamics of internal market, this study proposes Internal Absorption as an instrument for measuring market size for economies which confront large trade deficit over a longer period of time. The study empirically examines the impacts of Internal Absorption along with trade openness and gross private investment on FDI inflows in Pakistan. The ARDL approach to co-integration and ECM based on ARDL is used to test the existence of long run relationships among variables for the period 1976-2009. The result establishes strong positive relationship between Internal Absorption and FDI inflows in short as well as in the long run.Keywords. Foreign direct investment, Internal absorption, Trade openness, Private investment.JEL. F18, F21, F23, O47

Investigation of Biological Process for the Conversion of Bark Biomass to Bio-based Polyphenols

Due to increasing waste production and disposal problems arising from synthetic polymer production, there is a critical need to substitute these materials with biodegradable and renewable resources. The concept of green polymers has become more appealing due to the presence of large volumes of processing residuals from the timber and pulp industries. This, in turn, supports the idea of developing new polymers based on bark extractives. In this thesis, three comparative treatments i.e., enzymatic, alkaline, and UV/H2O2, have been conducted for the extraction of beetle infested lodgepole pine (BILP) and mixed aspen barks polyphenolic extractives. Use of laccases as biocatalysts to affect and enhance the catalytic properties of enzymes has been shown to be a promising solution for bark depolymerization. Furthermore, laccases are suitable for biotechnological applications that transform bark biomass into high valued bark biochemicals. The industrial and biotechnological application of ligninases is constantly increasing due to their multiple uses and applications in a diversity of processes. Bark depolymerization was conducted in submerged fermentation (SF) and we identified polyphenols/polyaromatic compounds after four weeks when the production media (PM) was induced with 50mg/100ml of each type of bark during the lag-phase. During SF where honey was used as a natural mediator substitute (NMS) in the PM, laccase activities were about 1.5 times higher than those found in comparable cultures without honey in the PM. These samples were analyzed by GC-MS. The laccase enzyme was purified using UNO sphere Q-1 anion exchange chromatography and the molecular weight was determined to be ~50kDa on 10% SDS-PAGE and laccase kinetic parameters including maximal velocity (Vmax), Michaelis constant (Km), and turnover number (Kcat) were calculated from a Lineweaver Burk plot. All calculated kinetic parameters of the laccase activity are substrate (ABTS) specific. Py-GC-MS analysis of bark showed differing effects of fungal activity on bark composition. Polyphenolics were separated in reverse-phase mode using HPLC with two selected wavelengths of 290 and 340 nm to improve separation. The replacement of conventional natural mediators (NM) by monofloral honey in production media, and investigation of the effect of fungi-derived laccases on bark polyphenols are studied for the first time by this thesis work.Ph.D

Investigation of Biological Process for the Conversion of Bark Biomass to Bio-based Polyphenols

Due to increasing waste production and disposal problems arising from synthetic polymer production, there is a critical need to substitute these materials with biodegradable and renewable resources. The concept of green polymers has become more appealing due to the presence of large volumes of processing residuals from the timber and pulp industries. This, in turn, supports the idea of developing new polymers based on bark extractives. In this thesis, three comparative treatments i.e., enzymatic, alkaline, and UV/H2O2, have been conducted for the extraction of beetle infested lodgepole pine (BILP) and mixed aspen barks polyphenolic extractives. Use of laccases as biocatalysts to affect and enhance the catalytic properties of enzymes has been shown to be a promising solution for bark depolymerization. Furthermore, laccases are suitable for biotechnological applications that transform bark biomass into high valued bark biochemicals. The industrial and biotechnological application of ligninases is constantly increasing due to their multiple uses and applications in a diversity of processes. Bark depolymerization was conducted in submerged fermentation (SF) and we identified polyphenols/polyaromatic compounds after four weeks when the production media (PM) was induced with 50mg/100ml of each type of bark during the lag-phase. During SF where honey was used as a natural mediator substitute (NMS) in the PM, laccase activities were about 1.5 times higher than those found in comparable cultures without honey in the PM. These samples were analyzed by GC-MS. The laccase enzyme was purified using UNO sphere Q-1 anion exchange chromatography and the molecular weight was determined to be ~50kDa on 10% SDS-PAGE and laccase kinetic parameters including maximal velocity (Vmax), Michaelis constant (Km), and turnover number (Kcat) were calculated from a Lineweaver Burk plot. All calculated kinetic parameters of the laccase activity are substrate (ABTS) specific. Py-GC-MS analysis of bark showed differing effects of fungal activity on bark composition. Polyphenolics were separated in reverse-phase mode using HPLC with two selected wavelengths of 290 and 340 nm to improve separation. The replacement of conventional natural mediators (NM) by monofloral honey in production media, and investigation of the effect of fungi-derived laccases on bark polyphenols are studied for the first time by this thesis work.Ph.D

Novel thermostable clostridial strains through protoplast fusion for enhanced biobutanol production at higher temperature—preliminary study

The objective of this study is to improve the thermal stability of clostridium strains for enhanced biobutanol production. Thermostable clostridia species were developed through protoplast fusion between mesophilic clostridial species (i.e., Clostridium beijerinckii and Clostridium acetobutylicum) and thermophilic clostridial species (i.e., Clostridium thermocellum). Production of biobutanol was examined in the present preliminary study using the clostridium strains and their protoplast fusants using sugar mixture with composition identical to that of wheat straw acid hydrolysate. Maximum biobutanol production of 9.4 g/L was achieved by a fused strain at 45 °C with total sugar consumption of 66% compared to that at 35 °C (i.e., 8.4 g/L production and 64% total sugar consumption). Glucose and xylose uptake rates were generally higher compared to all other individual sugars in the feedstock. In general, average cell concentrations were in close proximity for all parenting and fused strains at 35 °C; i.e., in the range of 5.12 × 107 to 5.49 × 107 cells/mL. Average cell concentration of fusants between the mesophilic clostridial species and the thermophilic clostridial species slightly increased to ~ 5.62 × 107 cells/mL at a higher temperature of 45 °C. These results, in addition to the ones obtained for the butanol production, demonstrate enhanced thermal stability of both fusants at a higher temperature (45 °C)

Novel thermostable clostridial strains through protoplast fusion for enhanced biobutanol production at higher temperature—preliminary study

The objective of this study is to improve the thermal stability of clostridium strains for enhanced biobutanol production. Thermostable clostridia species were developed through protoplast fusion between mesophilic clostridial species (i.e., Clostridium beijerinckii and Clostridium acetobutylicum) and thermophilic clostridial species (i.e., Clostridium thermocellum). Production of biobutanol was examined in the present preliminary study using the clostridium strains and their protoplast fusants using sugar mixture with composition identical to that of wheat straw acid hydrolysate. Maximum biobutanol production of 9.4 g/L was achieved by a fused strain at 45 °C with total sugar consumption of 66% compared to that at 35 °C (i.e., 8.4 g/L production and 64% total sugar consumption). Glucose and xylose uptake rates were generally higher compared to all other individual sugars in the feedstock. In general, average cell concentrations were in close proximity for all parenting and fused strains at 35 °C; i.e., in the range of 5.12 × 107 to 5.49 × 107 cells/mL. Average cell concentration of fusants between the mesophilic clostridial species and the thermophilic clostridial species slightly increased to ~ 5.62 × 107 cells/mL at a higher temperature of 45 °C. These results, in addition to the ones obtained for the butanol production, demonstrate enhanced thermal stability of both fusants at a higher temperature (45 °C).</p

Recent Advances in Applications of Acidophilic Fungi to Produce Chemicals

Processing of fossil fuels is the major environmental issue today. Biomass utilization for the production of chemicals presents an alternative to simple energy generation by burning. Lignocellulosic biomass (cellulose, hemicellulose and lignin) is abundant and has been used for variety of purposes. Among them, lignin polymer having phenyl-propanoid subunits linked together either through C-C bonds or ether linkages can produce chemicals. It can be depolymerized by fungi using their enzyme machinery (laccases and peroxidases). Both acetic acid and formic acid production by certain fungi contribute significantly to lignin depolymerization. Fungal natural organic acids production is thought to have many key roles in nature depending upon the type of fungi producing them. Biological conversion of lignocellulosic biomass is beneficial over physiochemical processes. Laccases, copper containing proteins oxidize a broad spectrum of inorganic as well as organic compounds but most specifically phenolic compounds by radical catalyzed mechanism. Similarly, lignin peroxidases (LiP), heme containing proteins perform a vital part in oxidizing a wide variety of aromatic compounds with H2O2. Lignin depolymerization yields value-added compounds, the important ones are aromatics and phenols as well as certain polymers like polyurethane and carbon fibers. Thus, this review will provide a concept that biological modifications of lignin using acidophilic fungi can generate certain value added and environmentally friendly chemicals

Recent Advances in Applications of Acidophilic Fungal Microbes for Bio-Chemicals

Lignocellulosic feedstock (cellulose, hemicellulose and lignin) has been used for a variety of purposes. Among them, lignin can produce value-added chemicals having phenyl-propanoid subunits known as core lignin, possessing either C-C bonds or ether linkages. It can be depolymerized by microbial activity together with certain enzymes (laccases and peroxidases). Both acetic acid and formic acid production by certain fungi contribute significantly to lignin depolymerization. Natural organic acids production by fungi has many key roles in nature that are strictly dependent upon organic acid producing fungus type. Enzymatic conversion of lignocellulosic is beneficial over other physiochemical processes. Laccases, the copper containing proteins oxidize a broad spectrum of inorganic as well as organic compounds but most specifically phenolic compounds by radical catalyzed mechanism. Similarly, lignin peroxidases (LiP), the heme containing proteins perform a vital part in oxidizing a wide variety of aromatic compounds with H2O2. Lignin depolymerization yields polyaromatics, the important ones are BTX (Benzene, Xylene and Toluene), found in several different configurations. However, most modern aromatics complexes enhance the production of p-xylene, benzene and sometimes o-xylene respectively. Thus, this review will provide a concept that chemical and biological modifications of lignin yield certain value added and environment friendly chemicals.</jats:p