Hydrothermal Synthesis and Crystal Structure of a Novel Bismuth Oxide: (K0.2Sr0.8)(Na0.01Ca0.25Bi0.74)O3

A novel distorted perovskite-type (K_0.2Sr_0.8)(Na_0.01Ca_0.25Bi_0.74)O₃ was prepared by a hydrothermal method using the starting materials NaBiO₃·nH₂O, Sr(OH)₂·8H₂O, Ca(OH)₂, and KOH. Single-crystal X-ray diffraction of the novel compound revealed a GdFeO₃-related structure belonging to the monoclinic system of the space group Cc with the following cell parameters: a = 11.8927 (17) Å, b = 11.8962 (15) Å, c = 8.4002 (10) Å, and β = 90.116 (9)°. The final R-factors were obtained as R ₁ = 0.0354 and wR ₂ = 0.0880 (using all the data). K⁺ and Sr²⁺ ions were distributed at four types of A-sites. On the other hand, four Bi⁵⁺-sites (Bi1, Bi2, Bi3, and Bi4) were occupied by four Ca²⁺ ions (Ca1, Ca2, Ca3, and Ca4), and the first three B-sites were occupied predominantly by Bi⁵⁺ with Na⁺ ions. The forth B-site was occupied predominantly by the Ca²⁺ ion with Bi⁵⁺ ions. Two types of B-sites, thus forming tilted distorted (Na/Ca/Bi)O₆ and (Bi/Ca)O₆ octahedra, have an ordering of 3:1 represented as (K/Sr)₄(Na/Ca/Bi)₃(Bi/Ca)O₁₂. The distorted (Na/Ca/Bi)O₆ and (Ca/Bi)O₆ octahedra formed a perovskite-type network by corner sharing with features closely matching those of a GdFeO₃-type structure. The novel compound is the first example of a perovskite-type bismuth oxide containing only Bi⁵⁺ in a system without a Ba atom and has a unique ordering (3:1) of the B site. The compound showed photocatalytic activity for phenol degradation under visible light irradiation.

The effect and nature of N–H complexes in the control of the dominant photoluminescence transitions in UV-hydrogenated GaInNAs

A study of certain defects in GaInNAs, and their passivation. The passivation process could lead to more efficient photovoltaic devices.

Raising Backyard Poultry in Rural Bangladesh: Financial and Nutritional Benefits, but Persistent Risky Practices

Poultry is commonly raised by households in rural Bangladesh. In 2007, the Government of Bangladesh began a mass media campaign to disseminate 10 recommended precautions to prevent transmission of H5N1 from poultry to humans. This longitudinal study explored the contribution of backyard poultry on household economy and nutrition and compared poultry-raising practices to government recommendations. From 2009 to 2012, we enrolled a nationally representative sample of 2489 primary backyard poultry raisers from 115 rural villages selected by probability proportional to population size. Researchers interviewed the raisers to collect data on poultry-raising practices. They followed the raisers for 2-12 months to collect data on household income and nutrition from poultry. Income from backyard poultry flocks accounted for 2.8% of monthly household income. Return on annual investment (ROI) per flock was 480%. Yearly, median family consumption of eggs was one-fifth of the total produced eggs and three poultry from their own flock. Respondents' reported practices conflicted with government recommendations. Sixty per cent of raisers had never heard of avian influenza or 'bird flu'. Among the respondents, 85% handled sick poultry or poultry that died due to illness, and 49% slaughtered or defeathered sick poultry. In 37% of households, children touched poultry. Fifty-eight per cent never washed their hands with soap after handling poultry, while <1% covered their nose and mouth with a cloth when handling poultry. Only 3% reported poultry illness and deaths to local authorities. These reported practices did not improve during the study period. Raising backyard poultry in rural Bangladesh provides important income and nutrition with an excellent ROI. Government recommendations to reduce the risk of avian influenza transmission did not impact the behaviour of poultry producers. Further research should prioritize developing interventions that simultaneously reduce the risk of avian influenza transmission and increase productivity of backyard poultry.

Interdependence of Cultivar and Environment on Fiber Composition in Wheat Bran

Starch and cellulose are among the best known renewable reinforcing components. Scientists are continuously looking for various renewable sources such as flax, hemp, jute, and corn hulls with polymer matrixes to form composite materials and make structural biocomposites a reality. Wheat is a major cereal grain in the US and the world. During wheat milling, a large amount of wheat bran, a by-product, is disposed off as waste. The high percentage of water-insoluble fiber in wheat bran could be advantageous for reinforcing industrial material. However, the utilization of cellulosic fibers derived from wheat byproduct has not been explored in processing of biocomposites. Therefore, the objectives of this study were to characterize wheat bran fiber compositions including dry matter (DM), ash, crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), cellulose (Cell), hemicellulose (Hemi), calcium (Ca), fat, starch, and acid detergent lignin (ADL); identify the interrelationship between the fiber composition traits and the influence of the environment and genotype on these traits. The experiment included six diverse and popular hard red spring wheat (HRSW) cultivars commonly grown in spring wheat region of the Northern Plains of USA. The experiment was installed in three different environments in the Dakotas States, USA. Results from this study showed that the DM, ash, Ca, Cell, starch, and ADL contents were influenced mainly by environments. However, CP along with fat, ash and Ca contents were influenced by genotypes in addition to environment. All bran components were influenced by the genotype × environment (G × E) interactions. We observed significant negative correlation of Cell with CP and ADL which make wheat bran a suitable reinforcing industrial material. However surface treatment of bran fiber would make it even more efficient. These preliminary results indicate the potential use of wheat bran components as biocomposite, but further studies to elucidate more these finding are warranted.

Sustained activation of c-jun-terminal kinase (JNK) is closely related to arsenic trioxide-induced apoptosis in an acute myeloid leukemia (M2)-derived cell line, NKM-1

High concentrations (greater than 5 microM) of arsenic trioxide (As(2)O(3)) have been reported to be able to induce apoptosis in several malignant cells. We explored cell lines in which apoptosis was induced with a therapeutic concentration (1-2 microM) of As(2)O(3), and found that 1 microM of As(2)O(3) induced apoptosis in the NKM-1 cell line, which was established from a patient with acute myeloid leukemia (M2). Apoptosis induced by 1 microM of As(2)O(3) in NKM-1 cells was accompanied by an increased cellular content of H(2)O(2), a decreased mitochondrial membrane potential (Deltapsim), and activation of caspase-3. C-Jun-terminal kinase (JNK) was activated only in NKM-1 cells and arsenic-sensitive NB4 cells, but not in arsenic-insensitive HL-60 cells. Activation of JNK in NKM-1 was sustained from 6 to 24 h after As(2)O(3) treatment, and preceded changes in cellular H(2)O(2), Deltapsim, and caspase-3 activation. Moreover, addition of a JNK inhibitor reduced the percentage of apoptotic cells after the As(2)O(3) treatment. Taken together, in the M2 cell line NKM-1, 1 microM of As(2)O(3) induced sustained activation of JNK and apoptosis. This finding may provide a basis to select a subgroup other than acute promyelocytic leukemia, which can benefit from As(2)O(3) treatment.

Glyoxal and methylglyoxal induce lyoxal and methyglyoxal induce aggregation and inactivation of ERK in human endothelial cells

Increased production of glyoxal (GO) and methylglyoxal (MGO) under oxidative stress is harmful to the cells. In this study, we examined the early signaling effect of GO/MGO on cultured human umbilical vein endothelial cells. Both GO and MGO induced tyrosine phosphorylation and aggregation of a number of cellular proteins. Aggregation occurred mainly for cell surface proteins such as Flk-1 and VE-cadherin, but barely for the majority of intracellular proteins. Interestingly, however, GO/MGO caused both aggregation and dephosphorylation of intracellular phospho-ERK for inactivation. This phospho-ERK dephosphorylation was mediated by orthovanadate-sensitive phosphatase activity accompanying chemical recruitment of MKP-1 to the aggregated phospho-ERK. Evidence was provided that GO/MGO upregulated MKP-1 activity that in turn dephosphorylated possibly co-aggregated phospho-ERK efficiently for inactivation. These results together suggest that GO and MGO trigger a novel pathway for chemical reaction-mediated downregulation of ERK.

T-cell-immunity-based inhibitory effects of orally administered herbal medicine juzen-taiho-to on the growth of primarily developed melanocytic tumors in RET-transgenic mice

We examined the effect of oral administration of juzen-taiho-to, one of the most popular herbal medicines in Japan, on primary melanocytic tumor growth in RET-transgenic mice. There was virtually no difference between the lengths of tumor-free stages in the juzen-taiho-to-treated mice and the untreated littermate control mice. The rate of tumor growth in the juzen-taiho-to-treated mice, however, was greatly suppressed during the entire period after the initial tumor development. Correspondingly, the life span of juzen-taiho-to-treated transgenic mice was longer (over 6 mo in mean value) than that of control mice. We partially elucidated the mechanism of the antitumor effect of juzen-taiho-to. The addition of juzen-taiho-to at any of a wide range (50-1600 microg per ml) of concentrations to in vitro cultures of Mel-Ret cells, a malignant melanoma cell line derived from a RET-transgenic mouse, caused neither cell death nor cell cycle arrest directly. The addition of 50-400 microg per ml of juzen-taiho-to to cultures of murine spleen cells, however, promoted their DNA synthesis. More importantly, peritoneal exudate cells from the juzen-taiho-to-treated transgenic mice, in which the ratio and number of T cells were increased, displayed an antitumor immunity against Mel-Ret cells in vitro. Interestingly, the peritoneal-exudate-cell-associated antitumor immunity was further augmented by the addition of 200-400 microg per ml of juzen-taiho-to in vitro. This immunity, which was primarily conveyed by Thy-1+ T cells, was antigen (RET/melanoma) specific and cytotoxic. Amongst various chemical ingredients of juzen-taiho-to examined in this study, glycirrhizin displayed an action, partially replacing that of juzen-taiho-to, in promoting anti-Mel-Ret immunity when supplementarily added in vitro. These results suggest that juzen-taiho-to suppresses once-developed primary melanocytic tumors through potentiation of T-cell-mediated antitumor cytotoxic immunity in vivo.

Glyoxal and methylglyoxal trigger distinct signals for map family kinases and caspase activation in human endothelial cells

Carbonyl compounds with diverse carbon skeletons may be differentially related to the pathogenesis of vascular diseases. In this study, we compared intracellular signals delivered into cultured human umbilical vein endothelial cells (HUVECs) by glyoxal (GO) and methylglyoxal (MGO), which differ only by a methyl group. Depending on their concentrations, GO and MGO promoted phosphorylations of ERK1 and ERK2, which were blocked by the protein-tyrosine kinase (PTK) inhibitors herbimycin A and staurosporine, thereby being PTK-dependent. GO and MGO also induced phosphorylations of JNK, p38 MAPK, and c-Jun, either PTK-dependently (GO) or -independently (MGO). Next, we found that MGO, but not GO, induced degradation of poly(ADP-ribose) polymerase (PARP) as the intracellular substrate of caspase-3. Curcumin and SB203580, which inhibit JNK and p38 MAPK signaling pathways, but not herbimycin A/staurosporine, prevented the MGO-induced PARP degradation. We then found that MGO, but not GO, reduced the intracellular glutathione level, and that cysteine, but not cystine, inhibited the MGO-mediated activation of ERK, JNK, p38 MAPK, or c-Jun more extensively than did lysine or arginine. In addition, all the signals triggered by GO and MGO were blocked by amino guanidine (AG), which traps carbonyls. These results demonstrated that GO and MGO triggered two distinct signal cascades, one for PTK-dependent control of ERK and another for PTK-independent redox-linked activation of JNK/p38 MAPK and caspases in HUVECs, depending on the structure of the carbon skeleton of the chemicals.

Acrolein induces activation of the epidermal growth factor receptor of human keratinocytes for cell death

Acrolein, which is a highly reactive formaldehyde generated by lipid peroxidation, can affect skin and cause various disorders. The effect of exposure of human keratinocytes to acrolein on cell surface-oriented signal transduction into cells was examined. Incubation of human keratinocytes with a relatively low concentration (50 microM) of acrolein caused a prompt and selective induction of tyrosine phosphorylation of the epidermal growth factor receptor (EGFR) as a 180-kDa molecule during the period from 5-30 min after the start of incubation. This early event was followed by an increase in the density and number of phosphotyrosine-containing proteins during the period from 60-120 min after the start of incubation. The catalytic activity of EGFR as measured by the levels of autophorphorylation and phosphorylation of an exogenously added substrate, casein, in in vitro kinase assay, greatly increased as early as 1 min after the start of incubation and then decreased gradually 30 min later. MAP family kinases, including ERK, JNK, and p38 kinase, and the potentially downstream transcription factor c-Jun were all promoted for phosphorylation/activation during a period of 5-30 min. Selective prompt phosphorylation/activation of EGFR followed by phosphorylation of MAP family kinases and c-Jun and their blockade by a specific EGFR inhibitor, AG1478, suggested that activation of EGFR is the major, and possibly single, cell surface element for intracellular signal transduction in acrolein-treated cells. Incubation of human keratinocytes with 50 microM of acrolein induced atypical apoptosis with morphologic apoptotic features with low-grade oligonucleoside-sized DNA fragmentation. Partial inhibition of such a cytopathic effect of acrolein on human keratinocytes by preincubation with AG1478 suggests the involvement of an EGFR-mediated signal pathway for atypical apoptosis. These results provide new information on acrolein-induced cell surface-oriented signal transduction to human keratinocytes, and this information may be useful for understanding the pathogenesis of a number of skin diseases in response to environmental acrolein and acrolein-generating ultraviolet irradiation.

Cepharanthine activates caspases and induces apoptosis in Jurkat and K562 human leukemia cell lines

Cepharanthine (CEP) is a known membrane stabilizer that has been widely used in Japan for the treatment of several disorders such as anticancer therapy-provoked leukopenia. We here report that apoptosis was induced by low concentrations (1-5 microM) of CEP in a human leukemia T cell line, Jurkat, and by slightly higher concentrations (5-10 microM) in a human chronic myelogenous leukemia (CML) cell line K562, which expresses a p210 antiapoptotic Bcr-Abl fusion protein. Induction of apoptosis was confirmed in both Jurkat and K562 cells by DNA fragmentation and typical apoptotic nuclear change, which were preceded by disruption of mitochondrial membrane potential and were induced through a Fas-independent pathway. CEP treatment induced activation of caspase-9 and -3 accompanied by cleavage of PARP, Bid, lamin B1, and DFF45/ICAD in both Jurkat and K562 cells, whereas caspase-8 activation and Akt cleavage were observed only in Jurkat cells. The CEP-induced apoptosis was completely blocked by zVAD-fmk, a broad caspase inhibitor. Interestingly, CEP treatment induced remarkable degradation of the Bcr-Abl protein in K562 cells, and this degradation was prevented partially by zVAD-fmk. When used in combination with a nontoxic concentration of herbimycin A, lower concentrations (2-5 microM) of CEP induced obvious apoptosis in K562 cells with rapid degradation or decrease in the amount of Bcr-Abl and Akt proteins. Our results suggest that CEP, which does not have bone marrow toxicity, may possess therapeutic potential against human leukemias, including CML, which is resistant to anticancer drugs and radiotherapy.

Arsenite induces apoptosis of murine T lymphocytes through membrane raft-linked signaling for activation of c-Jun amino-terminal kinase

Because of its dual roles in acute toxicity and in therapeutic application in cancer treatment, arsenic has recently attracted a renewed attention. In this study, we report NaAsO(2)-induced signal cascades from the cell surface to the nucleus of murine thymic T lymphocytes that involve membrane rafts as an initial signal transducer. NaAsO(2) induced apoptosis through fragmentation of DNA, activation of caspase, and reciprocal regulation of Bcl-2/Bax with the concomitant reduction of membrane potential. We demonstrated that NaAsO(2)-induced caspase activation is dependent on curcumin-sensitive c-Jun amino-terminal kinase and barely dependent on SB203580-sensitive p38 kinase or PD98059-sensitive extracellular signal-regulated kinase. Additionally, staurosporine, which severely inhibited the activation of mitogen-activated protein (MAP) family kinases and c-Jun, partially blocked the NaAsO(2)-mediated signal for poly(ADP-ribose) polymerase (PARP) degradation. Potentially as the initial cell surface event for intracellular signaling, NaAsO(2) induced aggregation of GPI-anchored protein Thy-1 and superoxide production. This Thy-1 aggregation and subsequent activation of MAP family kinase and c-Jun and the degradation of PARP induced by NaAsO(2) were all inhibited by DTT, suggesting the requirement of interaction between arsenic and protein sulfhydryl groups for those effects. beta cyclodextrin, which sequestrates cholesterol from the membrane rafts, inhibited NaAsO(2)-induced activation of protein tyrosine kinases and MAP family kinases, degradation of PARP, and production of superoxide. In addition, beta cyclodextrin dispersed NaAsO(2)-induced Thy-1 clustering. These results suggest that a membrane raft integrity-dependent cell surface event is a prerequisite for NaAsO(2)-induced protein tyrosine kinase/c-Jun amino-terminal kinase activation, superoxide production, and downstream caspase activation.

Molecular mechanism of activation and superactivation of Ret tyrosine kinases by ultraviolet light irradiation

The catalytic activities of Ret tyrosine kinases as the products of oncogene RET with multiple endocrine neoplasia type 2A (Ret-MEN2A) or 2B (Ret-MEN2B) mutations and the hybrid gene from c-RET and RFP (Rfp-Ret) were higher than those of c-Ret. We demonstrated that ultraviolet light (UV) irradiation induced activation of c-Ret and superactivation of genetically mutated, and thereby constitutively activated, Ret-MEN2A, Ret-MEN2B, and Rfp-Ret. We found that small proportions of c-Ret and Ret-MEN2B and a large proportion of MEN2A were dimerized due to disulfide bonds and that high kinase activity resided in these fractions. The UV-induced activation of c-Ret and superactivation of Ret-MEN2A and Ret-MEN2B were then shown to be closely associated with promotion of the disulfide bond-mediated dimerization of the Ret proteins. Furthermore, we showed that a large proportion of Rfp-Ret was dimerized or polymerized and that almost all kinase activities resided in the highly polymerized but not dimerized fraction. The UV-induced superactivation of Rfp-Ret was also found to be closely associated with promotion of polymerization but not with dimerization of Rfp-Ret. Further experiments revealed that UV induced intracellular dimerization and activation of the extracellular domain-deleted mutant Ret (Ret-PTC-1). Most importantly, the levels of basal kinase activity and dimerization of Ret-TPC-1-C376A, in which cysteine 376 in the tyrosine kinase domain of Ret-TPC-1 was replaced with alanine, were low and were not increased by UV irradiation. These results suggest that the cysteine at this position works as the primary target of dimerization of Ret proteins inside the cell for both the maintenance of the basal kinase activity and its promotion by UV, possibly in co-operation with the cysteine(s) in the extracellular domain of Ret-MEN2A and Rfp-Ret, which is the target of dimerization and polymerization outside the cell. The potential biological significance of the UV-mediated superactivation of mutant Ret through the newly proposed mechanism in oncogenesis is discussed.

Effects of Different Media and Organic Additives Interaction on In Vitro Regeneration of Dendrobium Orchid

Interaction of different media and organic additives showed significant effects on growth and development of protocorm like bodies (PLBs) and subsequent plantlets regeneration of Dendrobium orchid in laboratory conditions. Except the length of shoots and leaves, the highest values of all parameters were obtained from the interaction of ½MS medium with Sabri banana pulp. However, the longest shoots were found in KC medium with Sabri banana pulp and the longest leaves were found in both KC and ½MS media with Sabri banana pulp. Key words: Interaction, regeneration, Dendrobium, media and organic additives.  doi:10.3329/jard.v6i1.1659 J Agric Rural Dev 6(1&2), 69-74, June 2008