Identification and characterization of annexin gene family in rice

Plant annexins are Ca²⁺-dependent phospholipid-binding proteins and are encoded by multigene families. They are implicated in the regulation of plant development as well as protection from drought and other stresses. They are well characterized in Arabidopsis, however no such characterization of rice annexin gene family has been reported thus far. With the availability of the rice genome sequence information, we have identified ten members of the rice annexin gene family. At the protein level, they share 16–64% identity with predicted molecular masses ranging from 32 to 40 kDa. Phylogenetic analysis of rice annexins together with annexins from other monocots led to their classification into five different orthologous groups and share similar motif patterns in their protein sequences. Expression analysis by real-time RT-PCR revealed differential temporal and spatial regulation of these genes. The rice annexin genes are also found to be regulated in seedling stage by various abiotic stressors including salinity, drought, heat and cold. Additionally, in silico analysis of the putative upstream sequences was analyzed for the presence of stress-responsive cis-elements. These results provide a basis for further functional characterization of specific rice annexin genes at the tissue/developmental level and in response to abiotic stresses.     

Stress, suspension and resistance to infection

Immune function is altered in stressful situations, including space flight. This may result in increased risk of infection. Antiorthostatic suspension has been used to study the effects of space flight-like conditions on immunity. The mechanisms of promoting infection in stressful situations have not been defined, but catecholamines could play a role. In the present study gram negative bacteria grown with catecholamines showed enhanced bacterial growth compared to controls. Additionally, antiorthostatically suspended mice infected with Klebsiella pneumoniae showed decreased survival compared to restrained or normally caged controls. Therefore, stress-induced enhanced bacterial growth and immunosuppression could play a role in suspension-induced enhanced mortality due to infection.     

Soil-Transmitted Helminths and Associated Factors among Pre-School Children in Butajira Town,South-Central Ethiopia: A Community-Based Cross-Sectional Study

Background

Soil-transmitted helminths (STH) remain a major public health problem, particularly in tropical and sub-tropical regions of the world. Though infections are prevalent among all age groups, the world health organization (WHO) considers Pre-school age children (PSAC), school-aged children, and pregnant women as segments of population at high risk of STH morbidities.

Objective

This study aimed at determining the prevalence and infection intensity of STH and associated factors among PSAC in Butajira Town, south-central Ethiopia.

Methods

A community-based cross-sectional study was conducted from May to June, 2014 in Butajira Town. The PSAC were selected by systematic sampling technique and invited to participate in the present study. McMaster technique was employed for parasitological analysis of stool samples. Pearson’s Chi-square and Fisher’s exact tests were performed where appropriate to identify any association between STH infection and independent factors. Multivariate logistic regression model was fitted to identify independent predictors of STH among the PSAC. P-value less than 0.05 was considered statistically significant.

Results

A total of 377 (with 96% compliance rate) PSAC were able to provide complete data (socio-demographic information and stool sample). The study showed that 23.3% (88/377) PSAC were infected with one or more species of STH. Ascaris lumbricoides was the most prevalent STH (14.9%) followed by Trichuris trichiura (6.4%). The overall infection intensity, expressed as geometric mean for A. lumbricoides, T. trichiura, and hookworms were 229, 178, and 154 eggs per gram of stool, respectively. The multivariate logistic regression model estimated that being in the age group of 36–47 months (AOR: 2.5, 95% CI: 1.2–5.3, P = 0.016), untrimmed finger nail (AOR: 3.2, 95% CI: 1.8–5.5, P < 0.001), and not washing hands before a meal (AOR: 3.0, 95% CI: 1.7–5.4, P < 0.001) were independent predictors of STH infections among the children.

Conclusion

The present study showed that STH was a public health problem among PSAC in the study area necessitating annual deworming to control morbidities associated with STH. Besides, the existing health education program should also be strengthened to prevent re-infection.     

Nonclinical aspects of venous thrombosis in pregnancy

Pregnancy is a hypercoagulable state which carries an excess risk of maternal venous thrombosis. Endothelial injury, alterations in blood flow and activation of the coagulation pathway are proposed to contribute to the hypercoagulability. The risk for thrombosis may be accentuated by certain drugs and device implants that directly or indirectly affect the coagulation pathway. To help ensure that these interventions do not result in adverse maternal or fetal outcomes during pregnancy, gravid experimental animals can be exposed to such treatments at various stages of gestation and over a dosage range that would identify hazards and inform risk assessment. Circulating soluble biomarkers can also be evaluated for enhancing the assessment of any increased risk of venous thrombosis during pregnancy. In addition to traditional in vivo animal testing, efforts are under way to incorporate reliable non‐animal methods in the assessment of embryofetal toxicity and thrombogenic effects. This review summarizes hemostatic balance during pregnancy in animal species, embryofetal development, biomarkers of venous thrombosis, and alterations caused by drug‐induced venous thrombosis. Birth Defects Research (Part C) 105:190–200, 2015. © 2015 Wiley Periodicals, Inc.     

Fine Root Morphology,Biochemistry and Litter Quality Indices of Fast- and Slow-growing Woody Species in Ethiopian Highland Forest

Fine root turnover of trees is a major C input to soil. However, the quality of litter input is influenced by root morphological traits and tissue chemical composition. In this study, fine roots of ten tropical woody species were collected from an Afromontane forest in the northern highlands of Ethiopia. The fine roots were analysed for root morphological traits and tissue chemistry measured as proxy carbon fractionations. Based on stem increment, the 10 species were divided into faster- and slower-growing species. Faster-growing species exhibited higher specific root length (1362 cm g^?1) than slower-growing species (923 cm g^?1). Similarly specific root area was higher in faster-growing species (223 cm² g^?1) than in slower-growing species (167 cm² g^?1). Among the carbon fractions, the acid-insoluble fraction (AIF) was the highest (44–51%). The carbon content, AIF, and the lignocellulose index were higher for slower-growing species. Root tissue density was lower in faster-growing species (0.33 g cm^?3) than slower-growing species (0.40 g cm^?3) and showed a strong positive correlation with carbon content (r ² = 0.84) and the AIF (r _pearson = 0.93). The morphological traits of fine roots between faster- and slower-growing species reflect the ecological strategy they employ. Slower-growing species have a higher tissue density which may reflect a greater longevity.     

Isolation and characterization of methanogenic bacteria from rice paddies

Abstract Enrichment cultures for H₂-CO₂, methanol- or acetate-utilizing methanogens were prepared from two rice field soil samples. All the cultures except one acetate enrichment showed significant methane production. Pure cultures of Methanobacterium - and Methanosarcina -like organisms were isolated from H₂-CO₂ and methanol enrichment cultures, respectively, and were characterized for various nutritional and growth conditions. The organisms had an optimal pH range of 6.4–6.6 and a temperature optimum of 37°C. The Methanobacterium isolates were able to utilize H₂-CO₂ but no other substrates as sole energy source, while the Methanosarcina isolates were able to utilize methanol, methylamines or H₂-CO₂ as sole energy sources. Both Methanobacterium isolates and one isolate of Methanosarcina were able to use dinitrogen as the sole source of nitrogen for growth. The isolates used several sulfur compounds as sole sources of sulfur.     

Binding of caffeine with caffeic acid and chlorogenic acid using fluorescence quenching,UV/vis and FTIR spectroscopic techniques

The interactions of caffeine (CF) with chlorogenic acid (CGA) and caffeic acid (CFA) were investigated by fluorescence quenching, UV/vis and Fourier transform infrared (FTIR) spectroscopic techniques. The results of the study indicated that the fluorescence quenching between caffeine and hydroxycinnamic acids could be rationalized in terms of static quenching or the formation of non‐fluorescent CF–CFA and CF–CGA complexes. From fluorescence quenching spectral analysis, the quenching constant (K_SV), quenching rate constant (k_q), number of binding sites (n), thermodynamic properties and conformational changes of the interaction were determined. The quenching constants (K_SV) between CF and CGA, CFA are 1.84 × 10⁴ and 1.04 × 10⁴ L/mol at 298 K and their binding site n is ~ 1. Thermodynamic parameters determined using the Van't Hoff equation indicated that hydrogen bonds and van der Waal's forces have a major role in the reaction of caffeine with caffeic acid and chlorogenic acid. The 3D fluorescence, UV/vis and FTIR spectra also showed that the binding of CF with CFA and CGA induces conformational changes in CFA and CGA. Copyright © 2015 John Wiley & Sons, Ltd.     

Mycobacterium tuberculosis Complex and HIV Co-Infection among Extrapulmonary Tuberculosis Suspected Cases at the University of Gondar Hospital,Northwestern Ethiopia

Background

Extrapulmonary Tuberculosis (EPTB) and Human Immunodeficiency Virus (HIV) infection are interrelated as a result of immune depression. The aim of this study was to determine the prevalence of Mycobacterium tuberculosis complex isolates and the burden of HIV co-infection among EPTB suspected patients.

Method

An institution based cross-sectional study was conducted among EPTB suspected patients at the University of Gondar Hospital. Socio-demographic characteristics and other clinical data were collected using a pretested questionnaire. GeneXpert MTB/RIF assay was performed to diagnosis Mycobacterium tuberculosis complex and Rifampicin resistance. All samples were also investigated by cytology and culture. The HIV statuses of all patients were screened initially by KHB, and all positive cases were further re-tested by STAT-pack. Data was analyzed using SPSS version 20 computer software and a P-value of < 0.05 was taken as statistically significant.

Results

A total of 141 extrapulmonary suspected patients were enrolled in this study. The overall prevalence of culture confirmed extrapulmonary tuberculosis infection was 29.8%, but the GeneXpert result showed a 26.2% prevalence of Mycobacterium tuberculosis complex infection. The 78.4% prevalence of extrapulmonary tuberculosis infection was found to be higher among the adult population. The prevalence of HIV infection among EPTB suspected patients was 14.1%, while it was 32.4% among GeneXpert-confirmed extrapulmonary TB cases (12/37). Tuberculosis lymphadenitis was the predominant (78.4%) type of EPTB infection followed by tuberculosis cold abscess (10.7%). Adult hood, previous history of contact with known pulmonary tuberculosis patients, and HIV co-infection showed a statistically significant association with extrapulmonary tuberculosis infection (P<0.013).

Conclusion

The prevalence of culture confirmed-EPTB infection was high, and a higher EPTB-HIV co-infection was also observed.     

Elemental metals as electron sources for biological methane formation from CO2

Several elemental metals were examined as potential electron donors for methanogenic bacteria, using both a single tube system where the metal was in direct contact with the cells, and a two-flask system, where metal and cells were not in direct contact, but had contact via the gas phase. With all organisms examined in the direct contact system, Fe^o, Al^o and Zn^o served as electron donors for methanogenesis; some organisms used Ni^o or Sn^o as low-level electron donors. Of the metals tested, methanogenesis from H₂+CO₂ was inhibited by direct contact with Zn^o or Cu^o, but not by Fe^o or Al^o. Ni^o and Co^o were inhibitory to some methanogens, with Ni^o being particularly inhibitory to the thermophilic strains tested. With all organisms examined in the two-flask system, Fe^o and Zn^o served as good electron sources for both methanogenesis and growth; Co^o generated a very low level of methane and Cu^o did not work at all. In either system V^o, Ti^o or Cd^o did not serve as electron donors. The results suggest that some elemental metals (notably Fe^o, Al^o and Zn^o) produce gaseous H₂ by cathodic depolarization which is then consumed by the methanogen, thus accelerating oxidation of the metal by its metabolic activity. All of these reactions are thermodynamically favorable; however, some other metals that are clearly favorable for such a reaction on thermodynamic grounds (Ti^o and V^o) are very stable and do not serve as electron donors.Preliminary results on this topic were presented at the Pan American Biodeterioration Society Meeting in Washington, D.C. July 28–31, 1988.     

PHOTOINHIBITION OF PHOTOSYNTHESIS IN ASTERIONELLA FORMOSA (BACILLARIOPHYCEAE)1, 2

A laboratory study was made of the inhibition of photosynthesis, as measured by the radiocarbon method, of Asterionella Formosa Hass. by light from tungsten halogen lamps of irradiances up to that of full sunlight. The observed inhibitions were of total fixation of carbon and were not due to greatly increased release of extracellular products of photosynthesis. Inhibition increased width irradiance and with time of exposure. It was greater at high temperature, at high oxygen concentrations and when the cells were nutrient deficient. Recovery from exposure to high irradiances took place both in the dark and at low irradiances. The inhibition, which is similar to that observed under natural conditions, has the characteristics of photooxidative damage to both photochemical and dark reaction mechanisms.